web development

Dynamic Filters in Pure CSS

While working on something else entirely¹, I had a random thought:

Could the :checked and and :has pseudo-classes and the subsequent-sibling (~) selector be combined to perform interactive filtering without JavaScript?

Turns out, yes. Have a play with the filters on the side of this. You can either use:

“OR” mode, so you can show e.g. “all mammals and carnivores”, or
“AND” mode, so you can show e.g. “all mammals that are carnivores”.

Filter the animals!

(if it doesn’t work right where you are, e.g. in a feed reader, you can view it “standalone”)

The source code is available to download under the Unlicense, but the animal images are CC-BY licensed (with thanks to Aslan Almukhambetov).

How does it work?

There’s nothing particularly complicated here, although a few of the selectors are a little verbose.

First, we set the initial state of each animal. In “OR” mode, they’re hidden, because each selected checkbox is additive. In “AND” mode, they’re shown, because checking a checkbox can only ever remove an animal from the result set:

#filters:has(#filter-or:checked) ~ #animals .animal {
  display: none;
}

#filters:has(#filter-and:checked) ~ #animals .animal {
  display: flex;
}

The magic of the :has pseudo-class is that it doesn’t change the scope, which means that after checking whether “AND” or “OR” is checked within the #filters, the #animals container is still an adjacent element.

Touchscreen interactive restaurant menu with filter categories on the left and dishes for selection in the centre. — Next time you’re implementing a filter interface, like this restaurant menu, perhaps ask whether you actually *need* JavaScript.

Then all we need to do is to use daisy-chain :has to show animals with a particular class if that class is checked in “OR” mode, or to hide animals that don’t have a particular class in “AND” mode. Here’s what that looks like:

#filters:has(#filter-or:checked):has(#aquatic:checked)  ~ #animals .aquatic,
#filters:has(#filter-or:checked):has(#bird:checked)     ~ #animals .bird,
...
#filters:has(#filter-or:checked):has(#reptile:checked)  ~ #animals .reptile {
  display: flex;
}

#filters:has(#filter-and:checked):has(#aquatic:checked) ~ #animals .animal:not(.aquatic),
#filters:has(#filter-and:checked):has(#bird:checked)    ~ #animals .animal:not(.bird),
...
#filters:has(#filter-and:checked):has(#reptile:checked) ~ #animals .animal:not(.reptile) {
  display: none;
}

It could probably enjoy an animation effect to make it clearer when items are added and removed², but that’s a consideration for another day.

Many developers would be tempted to use JavaScript to implement the client-side version of a filter like this. And in some cases, that might be the right option.

But it’s always worth remembering that:

A CSS solution is almost-always more-performant than a JS one.
A JS solution is usually less-resilient than a CSS one: a CDN failure, unsupported API, troublesome content-blocker or syntax error will typically have a much larger impact on JavaScript.
For the absolutely maximum compatibility, consider what you can do in plain HTML, or on the server-side, and treat anything on the client-side as progressive enhancement.

Footnotes

¹ The thing I was actually working on when I got distracted was an OAuth provider implementation for Three Rings, connected with work that took place at this weekend’s hackathon to (eventually) bring single-sign-on “across” Three Rings CIC’s products. Eventually being the operative word.

² Such an animation should, of course, be wrapped in a @media (prefers-reduced-motion: no-preference) media query!

Variable-aspect adaptive-bitrate video… in vanilla HTML?

The video below is presented in portrait orientation, because your screen is taller than it is wide.

The video below is presented in landscape orientation, because your screen is wider than it is tall.

The video below is presented in square orientation (the Secret Bonus Square Video!), because your screen has approximately the same width as as its height. Cool!

This is possible (with a single <video> element, and without any Javascript!) thanks to some cool HTML features you might not be aware of, which I’ll briefly explain in the video. Or scroll down for the full details.

Variable aspect-ratio videos in pure HTML

I saw a 2023 blog post by Scott Jehl about how he helped Firefox 120 (re)gain support for the <source media="..."> attribute. Chrome added support later that year, and Safari already had it. This means that it’s pretty safe to do something like this:

<video controls>
  <source src="squareish.mp4"
        media="(min-aspect-ratio: 0.95) and (max-aspect-ratio: 1.05)" />
  <source src="portrait.mp4"
        media="(orientation: portrait)" />
  <source src="landscape.mp4" />
</video>

This code creates a video with three sources: squareish.mp4 which is shown to people on “squareish” viewports, failing that portrait.mp4 which is shown to people whose viewports are taller than wide, and failing that landscape.mp4 which is shown to anybody else.

That’s broadly-speaking how the video above is rendered. No JavaScript needed.

Browsers only handle media queries on videos when they initially load, so you can’t just tip your phone over or resize the window: you’ll need to reload the page, too. But it works! Give it a go: take a look at the video in both portrait and landscape modes and let me know what you think¹.

Adding adaptive bitrate streaming with HLS

Here’s another cool technology that you might not have realised you could “just use”: adaptive bitrate streaming with HLS!

You’ve used adaptive bitrate streaming before, though you might not have noticed it. It’s what YouTube, Netflix, etc. are doing when your network connection degrades and you quickly get dropped-down, mid-video, to a lower-resolution version².

Turns out you can do it on your own static hosting, no problem at all. I used this guide (which has a great description of the parameters used) to help me:

ffmpeg -i landscape.mp4 \
       -filter_complex "[0:v]split=3[v1][v2][v3]; [v1]copy[v1out]; [v2]scale=w=1280:h=720[v2out]; [v3]scale=w=640:h=360[v3out]" \
       -map "[v1out]" -c:v:0 libx264 -x264-params "nal-hrd=cbr:force-cfr=1" -b:v:0 5M -maxrate:v:0 5M -minrate:v:0 5M -bufsize:v:0 10M -preset slow -g 48 -sc_threshold 0 -keyint_min 48 \
       -map "[v2out]" -c:v:1 libx264 -x264-params "nal-hrd=cbr:force-cfr=1" -b:v:1 3M -maxrate:v:1 3M -minrate:v:1 3M -bufsize:v:1 3M -preset slow -g 48 -sc_threshold 0 -keyint_min 48 \
       -map "[v3out]" -c:v:2 libx264 -x264-params "nal-hrd=cbr:force-cfr=1" -b:v:2 1M -maxrate:v:2 1M -minrate:v:2 1M -bufsize:v:2 1M -preset slow -g 48 -sc_threshold 0 -keyint_min 48 \
       -map a:0 -c:a:0 aac -b:a:0 96k -ac 2 \
       -map a:0 -c:a:1 aac -b:a:1 96k -ac 2 \
       -map a:0 -c:a:2 aac -b:a:2 48k -ac 2 \
       -f hls -hls_time 2 -hls_playlist_type vod -hls_flags independent_segments -hls_segment_type mpegts \
       -hls_segment_filename landscape_%v/data%02d.ts \
       -master_pl_name landscape.m3u8 \
       -var_stream_map "v:0,a:0 v:1,a:1 v:2,a:2" landscape_%v.m3u8

This command splits the H.264 video landscape.mp4 into three different resolutions: the original “v1” (1920×1080, in my case, with 96kbit audio), “v2” (1280×720, with 96kbit audio), and “v3” (640×360, with 48kbit audio), each with a resolution-appropriate maximum bitrate, and forced keyframes every 48th frame. Then it breaks each of those into HLS segments (.ts files) and references them from a .m3u8 playlist.

The output from this includes:

Master playlist landscape.m3u8, which references the other playlists with reference to their resolution and bandwidth, so that browsers can make smart choices,
Playlists landscape_0.m3u8 (“v1”), landscape_1.m3u8 (“v2”), etc., each of which references the “parts” of that video,
Directories landscape_0/, landscape_1/ etc., each of which contain
data00.ts, data01.ts, etc.: the actual “chunks” that contain the video segments, which can be downloaded independently by the browser as-needed

Bringing it all together

We can bring all of that together, then, to produce a variable-aspect, adaptive bitrate, HLS-streamed video player… in pure HTML and suitable for static hosting:

<video controls>
  <source src="squareish.m3u8"
         type="application/x-mpegURL"
        media="(min-aspect-ratio: 0.95) and (max-aspect-ratio: 1.05)" />

  <source src="portrait.m3u8"
         type="application/x-mpegURL"
        media="(orientation: portrait)" />

  <source src="landscape.m3u8"
         type="application/x-mpegURL" />
</video>

You could, I suppose, add alternate types, poster images, and all kinds of other fancy stuff, but this’ll do for now.

That’ll “just work” in Safari and a handful of mobile browsers… but won’t display anything for most desktop browsers. Boo!

One solution is to also provide the standard .mp4 files as an alternate <source>, and that’s fine I guess, but you lose the benefit of HLS (and you have to store yet more files). But there’s a workaround:

Polyfill full functionality for all browsers

If you’re willing to use a JavaScript polyfill, you can make the code above work on virtually any device. I gave this a go, here, by:

Including the polyfill hls.js, and
Adding some JavaScript code that detects affected `<video>` elements and applying the fix if necessary:

// Find all <video>s which have HLS sources:
for( hlsVideo of document.querySelectorAll('video:has(source[type="application/x-mpegurl"]), video:has(source[type="vnd.apple.mpegurl"])') ) {
  // If the browser has native support, do nothing:
  if( hlsVideo.canPlayType('application/x-mpegurl') || hlsVideo.canPlayType('application/vnd.apple.mpegurl') ) continue;

  // If hls.js can't help fix that, do nothing:
  if ( ! Hls.isSupported() ) continue;

  // Find the best source based on which is the first one to match any applicable CSS media queries
  const bestSource = Array.from(hlsVideo.querySelectorAll('source')).find(source=>window.matchMedia(source.media).matches)

  // Use hls.js to attach the best source:
  const hls = new Hls();
  hls.loadSource(bestSource.src);
  hls.attachMedia(hlsVideo);
}

It makes me feel a little dirty to make a <video> depend on JavaScript, but if that’s the route you want to go down while we wait for HLS support to become more widespread (rather than adding different-typed sources) then that’s fine, I guess.

This was a fun dive into some technologies I’ve not had the chance to try before. A fringe benefit of being a generalist full-stack developer is that when you’re “between jobs” you get to play with all the cool things when you’re brushing up your skills before your next big challenge!

(Incidentally: if you think you might be looking to employ somebody like me, my CV is over there!)

Footnotes

¹ There definitely isn’t a super-secret “square” video on this page, though. No siree. (Shh.)

² You can tell when you get dropped to a lower-resolution version of a video because suddenly everybody looks like they’re a refugee from Legoland.

Deprecate React

I’m keeping an eye out for my next career move (want to hire me?). Off the back of that I’ve been brushing up on the kinds of skills that I might be asked to showcase in any kind of “tech test”.

Not the kind of stuff I can do with one hand tied behind my back¹, but the things for which I’d enjoy feeling a little more-confident². Stuff that’s on my CV that I’ve done and can do, but where I’d like to check before somebody asks me about it in an interview.

React? Sure, I can do that…

LinkedIn, GlassDoor, and bits of the Fediverse are a gold mine for the kinds of things that people are being asked to demonstrate in tech tests these days. Like this post:

On LinkedIn, Avantika Raj shares a coding question asked during their React Developer interview with Volkswagon Software Solutions. It reads: Create a traffic light component with green, yellow, and red lights. On clicking a button, the light should change. Initially, it should show green. After 2 minutes, it should automatically switch to red for 30 seconds, then yellow for 10 seconds, and repeat this cycle continuously. — I’d describe myself as a “stack-agnostic senior/principal full-stack/backend web developer/security engineer”³, and so this question – which feels like it’s a filter for a junior developer with a React specialisation – isn’t really my wheelhouse. Which makes it a perfect excuse for an hour of playing about with React.

My recent React experience has mostly involved Gutenberg blocks and WordPress theme component. This seemed like an excuse to check that I can wrangle a non-WordPress React stack.

Animated GIF showing traffic lights changing through their phases on-demand or on a toggleable timer. — This isn’t particularly sophisticated. I added customisable durations for each light, but otherwise it’s pretty basic.

Half an hour later, I’d proven to myself that yes, I could throw together a fresh application with React DOM and implement some React components, pass state around and whatnot.

Time to move on to the next thing, right? That’s what a normal person would do.

But that’s not the kind of person I am.

Let’s reimplement this as Web Components

What I found myself thinking was… man, this is chunky. React is… not the right tool for this job.

(Or, increasingly, any job. But I’ll get back to that.)

A minified production build of my new component and its dependencies came in at 202kB (62.3kB compressed). That feels pretty massive for something that does so-little. So as an experiment, I re-implemented my new React component as a vanilla JS Web Component using a custom element. Identical functionality, but no third-party library dependencies. Here’s what I got:

This one’s interactive. Press a button or two!

The Web Component version of this control has no dependency chain and uses no JSX, and so it has no transpilation step: the source version is production-ready. You could minify it, but modern HTTP compression makes the impact of that negligible anyway: the whole thing weighs in at 19.5kB (5.2kB compressed) without minification.

And while I appreciate of course that there’s much more to JavaScript complexity and performance than file sizes… and beyond that I appreciate that there’s a lot more to making great components than the resulting bundle size… it’s hard to argue that delivering the same functionality (and less fragility) in a twelfth of the payload isn’t significant.

But there’s a bigger point here:

React is the new jQuery

I’m alarmed by the fact that I’m still seeing job ads for “React developers”, with little more requirement than an ability to “implement things in React”.

From where I’m sitting, React is the new jQuery. It:

Was originally built to work around missing or underdeveloped JavaScript functionality
- e.g. React’s components prior to Web Components
- e.g. jQuery’s manipulation prior to document.querySelectorAll
Continued to be valuable as a polyfill and as a standard middleware while that functionality become commonplace
- e.g. React before Web Components became more standardised around 2018
- e.g. jQuery’s $.ajax until the Fetch API was a reliable replacement to XMLHttpRequest
No longer provides enough value to be worth using in a new project
- And yet somehow gets added “out of habit” for many years

If you’ve got a legacy codebase with lots of React in it, you’re still going to need React for a while. Just like how you’re likely to continue to need jQuery for a while until you can tidy up all those edge-cases where you’re using it.

(You might even be locked-in to using both React and jQuery for some time, if say you’ve got a plugin architecture that demands backwards-compatibility: I’m looking at you, WordPress!)

But just as you’re already (hopefully) working to slowly extricate your codebases from any now-unnecessary jQuery dependencies they have… you should be working on an exit plan for your React code, too. It’s done its time; it’s served its purpose: now it’s just a redundant dependency making your bundles cumbersome and harder to debug.

Everything React gives you on the client-side – components, state/hooks, routing⁴, etc. – is possible (and easy) in modern JavaScript supported in all major browsers. And if you still really want an abstraction layer, there are plenty of options (and they’re all a lot lighter than React!).

The bottom line is, I suppose…

You shouldn’t be hiring “React developers”!

If you’re building a brand new project, you shouldn’t be using React. It should be considered deprecated.

If you’ve got an existing product that depends on React… you should be thinking about how you’ll phase it out over time. And with that in mind, you want to be hiring versatile developers. They’ll benefit from some experience with React, sure, but unless they can also implement for the modern Web of tomorrow, they’ll just code you deeper into your dependency on React.

It’s time you started recruiting “Front-End Developers (React experience a plus)”. Show some long-term thinking! Or else the Web is going to move on without you, and in 5-10 years you’ll struggle to recruit people to maintain your crumbling stack.

You can download all my code and try it for yourself, if you like. The README has lots more information/spicy rants, and the whole thing’s under a public domain license so you can do whatever you like with it.

Footnotes

¹ Exploiting or patching an injection vulnerability, optimising an SQL query, implementing a WordPress plugin, constructing a CircleCI buildchain, expanding test coverage over a Rubygem, performing an accessibility audit of a web application, extending a set of high-performance PHP-backed REST endpoints, etc. are all – I’d hope! – firmly in the “hold my beer” category of tech test skills I’d ace, for example. But no two tech stacks are exactly alike, so it’s possible that I’ll want to brush up on some of the adjacent technologies that are in the “I can do it, but I might need to hit the docs pages” category.

² It’s actually refreshing to be learning and revising! I’ve long held that I should learn a new programming language or framework every year or two to stay fresh and to keep abreast of what’s going on in world. I can’t keep up with every single new front-end JavaScript framework any more (and I’m not sure I’d want to!)! But in the same way as being multilingual helps unlock pathways to more-creative thought and expression even if you’re only working in your native tongue, learning new programming languages gives you a more-objective appreciation of the strengths and weaknesses of what you use day-to-day. tl;dr: if you haven’t written anything in a “new” (to you) programming language for over a year, you probably should.

³ What do job titles even mean, any more? 😂 A problem I increasingly find is that I don’t know how to describe what I do, because with 25+ years of building stuff for the Web, I can use (and have used!) most of the popular stacks, and could probably learn a new one without too much difficulty. Did I mention I’m thinking about my next role? If you think we might “click”, I’d love to hear from you…

⁴ Though if you’re doing routing only on the client-side, I already hate you. Consider for example the SlimJS documentation which becomes completely unusable if a third-party JavaScript CDN fails: that’s pretty fragile!

WebDX: Does More Mean Better?

Enumerating Web features

The W3C‘s WebDX Community Group this week announced that they’ve reached a milestone with their web-features project. The project is an effort to catalogue browser support for Web features, to establish an understanding of the baseline feature set that developers can rely on.

That’s great, and I’m in favour of the initiative. But I wonder about graphs like this one:

The graph shows the increase in time of the number of features available on the Web, broken down by how widespread they are implemented across the browser corpus.

The shape of that graph sort-of implies that… more features is better. And I’m not entirely convinced that’s true.

Does “more” imply “better”?

Don’t get me wrong, there are lots of Web features that are excellent. The kinds of things where it’s hard to remember how I did without them. CSS grids are for many purposes an improvement on flexboxes; flexboxes were massively better than floats; and floats were an enormous leap forwards compared to using tables for layout! The “new” HTML5 input types are wonderful, as are the revolutionary native elements for video, audio, etc. I’ll even sing the praises of some of the new JavaScript APIs (geolocation, web share, and push are particular highlights).

But it’s not some kind of universal truth that “more features means better developer experience”. It’s already the case, for example, that getting started as a Web developer is harder than it once was, and I’d argue harder than it ought to be. There exist complexities nowadays that are barriers to entry. Like the places where the promise of a progressively-enhanced Web has failed (they’re rare, but they exist). Or the sheer plethora of features that come with caveats to their use that simply must be learned (yes, you need a <meta name="viewport">; no, you can’t rely on JS to produce content).

Meanwhile, there are technologies that were standardised, and that we did need, but that never took off. The <keygen> element never got implemented into the then-dominant Internet Explorer (there were other implementation problems too, but this one’s the killer). This made it functionally useless, which meant that its standard never evolved and grew. As a result, its implementation in other browsers stagnated and it was eventually deprecated. Had it been implemented properly and iterated on, we’d could’ve had something like WebAuthn over a decade earlier.

Which I guess goes to show that “more features is better” is only true if they’re the right features. Perhaps there’s some way of tracking the changing landscape of developer experience on the Web that doesn’t simply count enumerate a baseline of widely-available features? I don’t know what it is, though!

A simple web

Mostly, the Web worked fine when it was simpler. And while some of the enhancements we’ve seen over the decades are indisputably an advancement, there are also plenty of places where we’ve let new technologies lead us astray. Third-party cookies appeared as a naive consequence of first-party ones, but came to be used to undermine everybody’s privacy. Dynamic DOM manipulation started out as a clever idea to help with things like form validation and now a significant number of websites can’t even show their images – or sometimes their text – unless their JavaScript code gets downloaded and interpreted successfully.

A blog post, news article, or even an eCommerce site or social networking platform doesn’t need the vast majority of the Web’s “new” features. Those features are important for some Web applications, but most of the time, we don’t need them. But somehow they end up being used anyway.

Whether or not the use of unnecessary new Web features is a net positive to developer experience is debatable. But it’s certainly not often to the benefit of user experience. And that’s what I care about.

This blog post, of course, can be accessed with minimal features: it’s even available over ultra-lightweight Gemini at gemini://danq.me/posts/webdx-does-more-mean-better/, and I’ve also written it as plain text on my plain text blog (did you know about that?).

CSS Cycling Gradient Text

An amazing CSS effect by Ana Tudor:

Wow, this is real pretty!

(You can edit that text. Really: try it!)

I’ve only recently (thanks, Spencer!) gained any level of understanding about the use of SVG filters in CSS, so this is doubly-impressive to me.

Even More 1999!

Spencer’s filter

Last month I implemented an alternative mode to view this website “like it’s 1999”, complete with with cursor trails, 88×31 buttons, tables for layout¹, tiled backgrounds, and even a (fake) hit counter.

One thing I’d have liked to do for 1999 Mode but didn’t get around to would have been to make the images look like it was the 90s, too.

Back then, many Web users only had graphics hardware capable of displaying 256 distinct colours. Across different platforms and operating systems, they weren’t even necessarily the same 256 colours²! But the early Web agreed on a 216-colour palette that all those 8-bit systems could at least approximate pretty well.

I had an idea that I could make my images look “216-colour”-ish by using CSS to apply an SVG filter, but didn’t implement it.

But Spencer, a long-running source of excellent blog comments, stepped up and wrote an SVG filter for me! I’ve tweaked 1999 Mode already to use it… and I’ve just got to say it’s excellent: huge thanks, Spencer!

The filter coerces colours to their nearest colour in the “Web safe” palette, resulting in things like this:

Plenty of pictures genuinely looked like that on the Web of the 1990s, especially if you happened to be using a computer only capable of 8-bit colour to view a page built by somebody who hadn’t realised that not everybody would experience 24-bit colour like they did³.

Dithering

But not all images in the “Web safe” palette looked like this, because savvy web developers knew to dither their images when converting them to a limited palette. Let’s have another go:

Dithering introduces random noise to media⁴ in order to reduce the likelihood that a “block” will all be rounded to the same value. Instead; in our picture, a block of what would otherwise be the same colour ends up being rounded to maybe half a dozen different colours, clustered together such that the ratio in a given part of the picture is, on average, a better approximation of the correct colour.

The result is analogous to how halftone printing – the aesthetic of old comics and newspapers, with different-sized dots made from few colours of ink – produces the illusion of a continuous gradient of colour so long as you look at it from far-enough away.

The other year I read a spectacular article by Surma that explained in a very-approachable way how and why different dithering algorithms produce the results they do. If you’ve any interest whatsoever in a deep dive or just want to know what blue noise is and why you should care, I’d highly recommend it.

You used to see digital dithering everywhere, but nowadays it’s so rare that it leaps out as a revolutionary aesthetic when, for example, it gets used in a video game.

All of which is to say that: I really appreciate Spencer’s work to make my “1999 Mode” impose a 216-colour palette on images. But while it’s closer to the truth, it still doesn’t quite reflect what my website would’ve looked like in the 1990s because I made extensive use of dithering when I saved my images in Web safe palettes⁵.

Why did I take the time to dither my images, back in the day? Because doing the hard work once, as a creator of graphical Web pages, saves time and computation (and can look better!), compared to making every single Web visitor’s browser do it every single time.

Which, now I think about it, is a lesson that’s still true today (I’m talking to you, developers who send a tonne of JavaScript and ask my browser to generate the HTML for you rather than just sending me the HTML in the first place!).

Footnotes

¹ Actually, my “1999 mode” doesn’t use tables for layout; it pretty much only applies a CSS overlay, but it’s deliberately designed to look a lot like my blog did in 1999, which did use tables for layout. For those too young to remember: back before CSS gave us the ability to lay out content in diverse ways, it was commonplace to use a table – often with the borders and cell-padding reduced to zero – to achieve things that today would be simple, like putting a menu down the edge of a page or an image alongside some text content. Using tables for non-tabular data causes problems, though: not only is it hard to make a usable responsive website with them, it also reduces the control you have over the order of the content, which upsets some kinds of accessibility technologies. Oh, and it’s semantically-invalid, of course, to describe something as a table if it’s not.

² Perhaps as few as 22 colours were defined the same across all widespread colour-capable Web systems. At first that sounds bad. Then you remember that 4-bit (16 colour) palettes used to look look perfectly fine in 90s videogames. But then you realise that the specific 22 “very safe” colours are pretty shit and useless for rendering anything that isn’t composed of black, white, bright red, and maybe one of a few greeny-yellows. Ugh. For your amusement, here’s a copy of the image rendered using only the “very safe” 22 colours.

³ Spencer’s SVG filter does pretty-much the same thing as a computer might if asked to render a 24-bit colour image using only 8-bit colour. Simply “rounding” each pixel’s colour to the nearest available colour is a fast operation, even on older hardware and with larger images.

⁴ Note that I didn’t say “images”: dithering is also used to produce the same “more natural” feel for audio, too, when reducing its bitrate (i.e. reducing the number of finite states into which the waveform can be quantised for digitisation), for example.

⁵ I’m aware that my footnotes are capable of nerdsniping Spencer, so by writing this there’s a risk that he’ll, y’know, find a way to express a dithering algorithm as an SVG filter too. Which I suspect isn’t possible, but who knows! 😅

April Features!

I’m testing a handful of highly-experimental new features on my personal website using multivariate (“A/B”) testing.

Screenshot of the recent "Quickly Solving JigsawExplorer Puzzles" blog post with a new "Dark mode" switch hovering over it. — “Dark Mode” is just one of the new features I’m testing out.

If you visit within the next day or so you’re likely to be randomly-selected to try out one of them. (If you’re not selected, you can manually enable one of the experiments.)

I’d love to hear your feedback on these Very Serious New Features! Let me know which one(s) you see and whether you think they should become permanent fixtures on my site.

Home Page, 50% Off!

In August, I celebrated my blog – with its homepage weighing-in at a total of just 481kb – being admitted to Kev Quirk‘s 512kb club. 512kb club celebrates websites (often personal sites) whose homepage are neither “ultra minimal” or “link pages” but have a total size, including all assets, of under half a megabyte. It’s about making a commitment to a leaner, more-efficient Web.

My relatively-heavyweight homepage only just slipped in under the line. But, feeling inspired perhaps by some performance enhancements I’ve been planning this week at work, I decided to try to shave a little more off:

Now, at ~234kb, danq.me just beats the excellent gomakethings.com (it’s all those heavyweight fonts, Chris!).

Here’s what I changed:

The “recent article” tiles are dynamically sized based on their number, type, and the visitor’s screen resolution. But apart from the top one they’re almost never very large. Using thumbnail images for the non-first tile shaved off almost 160kb.

Not space-saving, but while I was in there I ensured that the first tile’s image – which almost-certainly comprises part of the Largest Contentful Paint – is never delivered with loading="lazy".
I was providing a shortcut icon in .ico format (<link rel="shortcut icon" href="/_q23t/icons/favicon-16-32-48-64-128.ico" />), which is pretty redundant nowadays because all modern browsers (and even IE11) support .png icons. I was already providing .png and .svg versions, but it turns out that some browsers favour the one with the (harmful?) rel="shortcut icon" over rel="icon" if both are present, and .ico files are – being based on Windows Bitmaps – horrendously inefficient.

By getting under the 250kb threshold, I’ve jumped up a league from Blue Team to Orange Team, so that’s nice too. I can’t see a meaningful path from where I’m at to Green Team (under 100kb) though, so this level might have to suffice.

Last-minute additions:

Here’s the PR updating my site’s record in the club
If you like the animation, here’s the JavaScript code I used to generate it (plus a quick crossfade made in Kdenlive)

The Stupidest CSS

Yesterday, I wrote the stupidest bit of CSS of my entire career.

Owners of online shops powered by WooCommerce can optionally “connect” their stores back to Woo.com. This enables them to manage their subscriptions to any extensions they use to enhance their store¹. They can also browse a marketplace of additional extensions they might like to consider, which is somewhat-tailored to them based on e.g. their geographical location²

In the future, we’ll be adding sponsored products to the marketplace listing, but we want to be transparent about it so yesterday I was working on some code that would determine from the appropriate API whether an extension was sponsored and then style it differently to make this clear. I took a look at the proposal from the designer attached to the project, which called for

the word “Sponsored” to appear alongside the name of the extension’s developer,
a stripe at the top in the brand colour of the extension, and
a strange green blob alongside it

That third thing seemed like an odd choice, but I figured that probably I just didn’t have the design or marketing expertise to understand it, and I diligently wrote some appropriate code.³

I even attached to my PR a video demonstrating how my code reviewers could test it without spoofing actual sponsored extensions.

After some minor tweaks, my change was approved. The designer even swung by and gave it a thumbs-up. All I needed to do was wait for the automated end-to-end tests to complete, and I’d be able to add it to WooCommerce ready to be included in the next-but-one release. Nice.

In the meantime, I got started on my next bit of work. This one also included some design work by the same designer, and wouldn’t you know it… this one also had a little green blob on it?

Then it hit me. The blobs weren’t part of the design at all, but the designer’s way of saying “look at this bit, it’s important!”. Whoops!

So I got to rush over to my (already-approved, somehow!) changeset and rip out the offending CSS: the stupidest bit of CSS of my entire career. Not bad code per se, but reasonable code resulting from a damn-stupid misinterpretation of a designer’s wishes. Brilliant.

Footnotes

¹ WooCommerce extensions serve loads of different purposes, like handling bookings and reservations and integrating with parcel tracking services.

² There’s no point us suggesting an extension that helps you calculate Royal Mail shipping rates if you’re not shipping from the UK, for example!

³ A fun side-effect of working on open-source software is that my silly mistake gets immortalised somewhere where you can go and see it any time you like!

Shiftless Progressive Enhancement

Progressive enhancement is a great philosophy for Web application development. Deliver all the essential basic functionality using the simplest standards available; use advanced technologies to add bonus value and convenience features for users whose platform supports them. Win.

In Three Rings, for example, volunteers can see a “starchart” of the volunteering shifts they’ve done recently, at-a-glance, on their profile page¹. In the most basic case, this is usable in its HTML-only form: even with no JavaScript, no CSS, no images even, it still functions. But if JavaScript is enabled, the volunteer can dynamically “filter” the year(s) of volunteering they’re viewing. Basic progressive enhancement.

If a feature requires JavaScript, my usual approach is to use JavaScript to add the relevant user interface to the page in the first place. Those starchart filters in Three Rings don’t appear at all if JavaScript is disabled. A downside to this approach is that the JavaScript necessarily modifies the DOM on page load, which introduces a delay to the page being interactive as well as potentially resulting in layout shift.

That’s not always the best approach. I was reminded of this today by the website of 7-year-old Shiro (produced with, one assumes, at least a little help from Saneef H. Ansari). Take a look at this progressively-enhanced theme switcher:

No layout shift, no DOM manipulation. And yet it’s still pretty clear what features are available.

The HTML that’s delivered over-the-wire provides a disabled <select> element, which gains the CSS directive cursor: not-allowed;, to make it clear to the used that this dropdown doesn’t do anything. The whole thing’s wrapped in a custom element.

When that custom element is defined by the JavaScript, it enhances the dropdown with an event listener that implements the theme changes, then enables the disabled <select>.

<color-schemer>
  <form>
    <label>
      Theme
      <select disabled>
        <option value="">System</option>
        <option value="dark">Dark</option>
        <option value="light" selected>Light</option>
      </select>
    </label>
  </form>
</color-schemer>

I’m not convinced by the necessity of the <form> if there’s no HTML-only fallback… and the <label> probably should use a for="..." rather than wrapping the <select>, but otherwise this code is absolutely gorgeous.

It’s probably no inconvenience to the minority of JS-less users to see a theme switcher than, when they go to use it, turns out to be disabled. But it saves time for virtually everybody not to have to wait for JavaScript to manipulate the DOM, or else to risk shifting the layout by revealing a previously-hidden element.

Altogether, this is a really clever approach, and I was pleased today to be reminded – by a 7-year-old! – of the elegance of this approach. Nice one Shiro (and Saneef!).

Footnotes

¹ Assuming that administrators at the organisation where they volunteer enable this feature for them, of course: Three Rings‘ permission model is robust and highly-customisable. Okay, that’s enough sales pitch.

Netscape’s Untold Webstories

I mentioned yesterday that during Bloganuary I’d put non-Bloganuary-prompt post ideas onto the backburner, and considered extending my daily streak by posting them in February. Here’s part of my attempt to do that:

Let’s take a trip into the Web of yesteryear, with thanks to our friends at the Internet Archive’s WayBack Machine.

The page we’re interested in used to live at http://www.netscape.com/comprod/columns/webstories/index.html, and promised to be a showcase for best practice in Web development. Back in October 1996, it looked like this:

The page is a placeholder for Netscape Webstories (or Web Site Stories, in some places). It’s part of a digital magazine called Netscape Columns which published pieces written by Marc Andreeson, Jim Barksdale, and other bigwigs in the hugely-influential pre-AOL-acquisition Netscape Communications.

This new series would showcase best practice in designing and building Web sites¹, giving a voice to the technical folks best-placed to speak on that topic. That sounds cool!

Those white boxes above and below the paragraph of text aren’t missing images, by the way: they’re horizontal rules, using the little-known size attribute to specify a thickness of <hr size=4>!²

Certainly you’re excited by this new column and you’ll come back in November 1996, right?

Oh. The launch has been delayed, I guess. Now it’s coming in January.

The <hr>s look better now their size has been reduced, though, so clearly somebody’s paying attention to the page. But let’s take a moment and look at that page title. If you grew up writing web pages in the modern web, you might anticipate that it’s coded something like this:

<h2 style="font-variant: small-caps; text-align: center;">Coming Soon</h2>

There’s plenty of other ways to get that same effect. Perhaps you prefer font-feature-settings: 'smcp' in your chosen font; that’s perfectly valid. Maybe you’d use margin: 0 auto or something to centre it: I won’t judge.

But no, that’s not how this works. The actual code for that page title is:

<center>
  <h2>
    <font size="+3">C</font>OMING
    <font size="+3">S</font>OON
  </h2>
</center>

Back when this page was authored, we didn’t have CSS³. The only styling elements were woven right in amongst the semantic elements of a page⁴. It was simple to understand and easy to learn… but it was a total mess⁵.

Anyway, let’s come back in January 1997 and see what this feature looks like when it’s up-and-running.

Nope, now it’s pushed back to “the spring”.

Under Construction pages were all the rage back in the nineties. Everybody had one (or several), usually adorned with one or more of about a thousand different animated GIFs for that purpose.⁶

Building “in public” was an act of commitment, a statement of intent, and an act of acceptance of the incompleteness of a digital garden. They’re sort-of coming back into fashion in the interpersonal Web, with the “garden and stream” metaphor⁷ taking root. This isn’t anything new, of course – Mark Bernstein touched on the concepts in 1998 – but it’s not something that I can ever see returning to the “serious” modern corporate Web: but if you’ve seen a genuine, non-ironic “under construction” page published to a non-root page of a company’s website within the last decade, please let me know!

RSS doesn’t exist yet (although here’s a fun fact: the very first version of RSS came out of Netscape!). We’re just going to have to bookmark the page and check back later in the year, I guess…

Okay, so February clearly isn’t Spring, but they’ve updated the page… to add a search form.

It’s a genuine <form> tag, too, not one of those old-fashioned <isindex> tags you’d still sometimes find even as late as 1997. Interestingly, it specifies enctype="application/x-www-form-urlencoded". Today’s developers probably don’t think about the enctype attribute except when they’re doing a form that handles file uploads and they know they need to switch it to enctype="multipart/form-data", (or their framework does this automatically for them!).

But these aren’t the only options, and some older browsers at this time still defaulted to enctype="text/plain". So long as you’re using a POST and not GET method, the distinction is mostly academic, but if your backend CGI program anticipates that special characters will come-in encoded, back then you’d be wise to specify that you wanted URL-encoding or you might get a nasty surprise when somebody turns up using LMB or something equally-exotic.

Anyway, let’s come back in June. The content must surely be up by now:

Oh come on! Now we’re waiting until August?

At least the page isn’t abandoned. Somebody’s coming back and editing it from time to time to let us know about the still-ongoing series of delays. And that’s not a trivial task: this isn’t a CMS. They’re probably editing the .html file itself in their favourite text editor, then putting the appropriate file:// address into their copy of Netscape Navigator (and maybe other browsers) to test it, then uploading the file – probably using FTP – to the webserver… all the while thanking their lucky stars that they’ve only got the one page they need to change.

We didn’t have scripting languages like PHP yet, you see⁸. We didn’t really have static site generators. Most servers didn’t implement server-side includes. So if you had to make a change to every page on a site, for example editing the main navigation menu, you’d probably have to open and edit dozens or even hundreds of pages. Little wonder that framesets caught on, despite their (many) faults, with their ability to render your navigation separately from your page content.

Okay, let’s come back in August I guess:

Now we’re told that we’re to come back… in the Spring again? That could mean Spring 1998, I suppose… or it could just be that somebody accidentally re-uploaded an old copy of the page.

Hey: the footer’s gone too? This is clearly a partial re-upload: somebody realised they were accidentally overwriting the page with the previous-but-one version, hit “cancel” in their FTP client (or yanked the cable out of the wall), and assumed that they’d successfully stopped the upload before any damage was done.

They had not.

I didn’t mention that top menu, did I? It looks like it’s a series of links, styled to look like flat buttons, right? But you know that’s not possible because you can’t rely on having the right fonts available: plus you’d have to do some <table> trickery to lay it out, at which point you’d struggle to ensure that the menu was the same width as the banner above it. So how did they do it?

The menu is what’s known as a client-side imagemap. Here’s what the code looks like:

<a href="/comprod/columns/images/nav.map">
  <img src="/comprod/columns/images/websitestories_ban.gif" width=468 height=32 border=0 usemap="#maintopmap" ismap>
</a><map name="mainmap">
  <area coords="0,1,92,24" href="/comprod/columns/mainthing/index.html">
  <area coords="94,1,187,24" href="/comprod/columns/techvision/index.html">
  <area coords="189,1,278,24" href="/comprod/columns/webstories/index.html">
  <area coords="280,1,373,24" href="/comprod/columns/intranet/index.html">
  <area coords="375,1,467,24" href="/comprod/columns/newsgroup/index.html">
</map>

The image (which specifies border=0 because back then the default behaviour for graphical browser was to put a thick border around images within hyperlinks) says usemap="#maintopmap" to cross-reference the <map> below it, which defines rectangular areas on the image and where they link to, if you click them! This ingenious and popular approach meant that you could transmit a single image – saving on HTTP round-trips, which were relatively time-consuming before widespread adoption of HTTP/1.1‘s persistent connections – along with a little metadata to indicate which pixels linked to which pages.

The ismap attribute is provided as a fallback for browsers that didn’t yet support client-side image maps but did support server-side image maps: there were a few! When you put ismap on an image within a hyperlink, then when the image is clicked on the href has appended to it a query parameter of the form ?123,456, where those digits refer to the horizontal and vertical coordinates, from the top-left, of the pixel that was clicked on! These could then be decoded by the webserver via a .map file or handled by a CGI program. Server-side image maps were sometimes used where client-side maps were undesirable, e.g. when you want to record the actual coordinates picked in a spot-the-ball competition or where you don’t want to reveal in advance which hotspot leads to what destination, but mostly they were just used as a fallback.⁹

Both client-side and server-side image maps still function in every modern web browser, but I’ve not seen them used in the wild for a long time, not least because they’re hard (maybe impossible?) to make accessible and they can’t cope with images being resized, but also because nowadays if you really wanted to make an navigation “image” you’d probably cut it into a series of smaller images and make each its own link.

Anyway, let’s come back in October 1997 and see if they’ve fixed their now-incomplete page:

Oh, they have! From the look of things, they’ve re-written the page from scratch, replacing the version that got scrambled by that other employee. They’ve swapped out the banner and menu for a new design, replaced the footer, and now the content’s laid out in a pair of columns.

There’s still no reliable CSS, so you’re not looking at columns: (no implementations until 2014) nor at display: flex (2010) here. What you’re looking at is… a fixed-width <table> with a single row and three columns! Yes: three – the middle column is only 10 pixels wide and provides the “gap” between the two columns of text.¹⁰

This wasn’t Netscape’s only option, though. Did you ever hear of the <multicol> tag? It was the closest thing the early Web had to a semantically-sound, progressively-enhanced multi-column layout! The author of this page could have written this:

<multicol cols=2 gutter=10 width=301>
  <p>
    Want to create the best possible web site? Join us as we explore the newest
    technologies, discover the coolest tricks, and learn the best secrets for
    designing, building, and maintaining successful web sites.
  </p>
  <p>
    Members of the Netscape web site team, recognized designers, and technical
    experts will share their insights and experiences in Web Site Stories. 
  </p>
</multicol>

That would have given them the exact same effect, but with less code and it would have degraded gracefully. Browsers ignore tags they don’t understand, so a browser without support for <multicol> would have simply rendered the two paragraphs one after the other. Genius!

So why didn’t they? Probably because <multicol> only ever worked in Netscape Navigator.

Introduced in 1996 for version 3.0, this feature was absolutely characteristic of the First Browser War. The two “superpowers”, Netscape and Microsoft, both engaged in unilateral changes to the HTML specification, adding new features and launching them without announcement in order to try to get the upper hand over the other. Both sides would often refuse to implement one-another’s new tags unless they were forced to by widespread adoption by page authors, instead promoting their own competing mechanisms¹¹.

Between adding this new language feature to their browser and writing this page, Netscape’s market share had fallen from around 80% to around 55%, and most of their losses were picked up by IE. Using <multicol> would have made their page look worse in Microsoft’s hot up-and-coming browser, which wouldn’t have helped them persuade more people to download a copy of Navigator and certainly wouldn’t be a good image on a soon-to-launch (any day now!) page about best-practice on the Web! So Netscape’s authors opted for the dominant, cross-platform solution on this page¹².

Anyway, let’s fast-forward a bit and see this project finally leave its “under construction” phase and launch!

Oh. It’s gone.

Sometime between October 1997 and February 1998 the long promised “Web Site Stories” section of Netscape Columns quietly disappeared from the website. Presumably, it never published a single article, instead remaining a perpetual “Coming Soon” page right up until the day it was deleted.

I’m not sure if there’s a better metaphor for Netscape’s general demeanour in 1998 – the year in which they finally ceased to be the dominant market leader in web browsers – than the quiet deletion of a page about how Netscape customers are making the best of the Web. This page might not have been important, or significant, or even completed, but its disappearance may represent Netscape’s refocus on trying to stay relevant in the face of existential threat.

Of course, Microsoft won the First Browser War. They did so by pouring a fortune’s worth of developer effort into staying technologically one-step ahead, refusing to adopt standards proposed by their rival, and their unprecedented decision to give away their browser for free¹³.

Footnotes

¹ Yes, we used to write “Web sites” as two words. We also used to consistently capitalise the words Web and Internet. Some of us still do so.

² In case it’s not clear, this blog post is going to be as much about little-known and archaic Web design techniques as it is about Netscape’s website.

³ This is a white lie. CSS was first proposed almost at the same time as the Web! Microsoft Internet Explorer was first to deliver a partial implementation of the initial standard, late in 1996, but Netscape dragged their heels, perhaps in part because they’d originally backed a competing standard called JavaScript Style Sheets (JSSS). JSSS had a lot going for it: if it had enjoyed widespread adoption, for example, we’d have had the equivalent of CSS variables a full twenty years earlier! In any case, back in 1996 you definitely wouldn’t want to rely on CSS support.

⁴ Wondering where the text and link colours come from? <body bgcolor="#ffffff" text="#000000" link="#0000ff" vlink="#ff0000" alink="#ff0000">. Yes really, that’s where we used to put our colours.

⁵ Personally, I really loved the aesthetic Netscape touted when using Times New Roman (or whatever serif font was available on your computer: webfonts weren’t a thing yet) with temporary tweaks to font sizes, and I copied it in some of my own sites. If you look back at my 2018 blog post celebrating two decades of blogging, where I’ve got a screenshot of my blog as it looked circa 1999, you’ll see that I used exactly this technique for the ordinal suffixes on my post dates! On the same post, you’ll see that I somewhat replicated the “feel” of it again in my 2011 design, this time using a stylesheet.

⁶ There’s a whole section of Cameron’s World dedicated to “under construction” banners, and that’s a beautiful thing!

⁷ The idea of “garden and stream” is that you publish early and often, refining as you go, in your garden, which can act as an extension of whatever notetaking system you use already, but publish mostly “finished” content to your (chronological) stream. I see an increasing number of IndieWeb bloggers going down this route, but I’m not convinced that it’s for me.

⁸ Another white lie. PHP was released way back in 1995 and even the very first version supported something a lot like server-side includes, using the syntax . But it was a little computationally-intensive to run willy-nilly.

⁹ Server-side imagemaps are enjoying a bit of a renaissance on .onion services, whose visitors often keep JavaScript disabled, to make image-based CAPTCHAs. Simply show the visitor an image and describe the bit you want them to click on, e.g. “the blue pentagon with one side missing”, then compare the coordinates of the pixel they click on to the knowledge of the right answer. Highly-inaccessible, of course, but innovative from a purely-technical perspective.

¹⁰ Nowadays, use of tables for layout – or, indeed, for anything other than tabular data – is very-much frowned upon: it’s often bad for accessibility and responsive design. But back before we had the features granted to us by the modern Web, it was literally the only way to get content to appear side-by-side on a page, and designers got incredibly creative about how they ~~mis~~used tables to lay out content, especially as browsers became more-sophisticated and began to support cells that spanned multiple rows or columns, tables “nested” within one another, and background images.

¹¹ It was a horrible time to be a web developer: having to make hacky workarounds in order to make use of the latest features but still support the widest array of browsers. But I’d still take that over the horrors of rendering engine monoculture!

¹² Or maybe they didn’t even think about it and just copy-pasted from somewhere else on their site. I’m speculating.

¹³ This turned out to be the master-stroke: not only did it partially-extricate Microsoft from their agreement with Spyglass Inc., who licensed their browser engine to Microsoft in exchange for a percentage of sales value, but once Microsoft started bundling Internet Explorer with Windows it meant that virtually every computer came with their browser factory-installed! This strategy kept Microsoft on top until Firefox and Google Chrome kicked-off the Second Browser War in the early 2010s. But that’s another story.

Lightboxes Without JavaScript

Because I like my blog to be as fast, accessible, and resilient, I try not to use JavaScript for anything I don’t have to¹. One example would be my “lightbox”: the way in which images are blown-up if you click on them:

My solution ensures that:

You can click an image and see a full-window popup dialog box containing a larger version of the image.
The larger version of the image isn’t loaded until it’s needed.
You can close the larger version with a close button. You can also use your browser’s back button.
You can click again to download the larger version/use your browser to zoom in further.
You can share/bookmark etc. the URL of a zoomed-in image and the recipient will see the same image (and return to the image, in the right blog post, if they press the close button).
No HTTP round trip is required when opening/closing a lightbox: it’s functionally-instantaneous.²
No JavaScript is used at all.

Visitors can click on images to see a larger version, with a “close” button. No JavaScript needed.

Here’s how it works –

The Markup

<figure id="img3336" aria-describedby="caption-img3336">
  <a href="#lightbox-img3336" role="button">
    <img src="small-image.jpg" alt="Alt text is important." width="640" height="480">
  </a>
  <figcaption id="caption-img3336">
    Here's the caption.
  </figcaption>
</figure>

... (rest of blog post) ...

<dialog id="lightbox-img3336" class="lightbox">
  <a href="large-image.jpg">
    <img src="large-image.jpg" loading="lazy" alt="Alt text is important.">
  </a>
  <a class="close" href="#img3336" title="Close image" role="button">×</a>
</dialog>

The HTML is pretty simple (and I automatically generate it, of course).

For each lightboxed image in a post, a <dialog> for that image is appended to the post. That dialog contains a larger copy of the image (set to loading="lazy" so the browser have to download it until it’s needed), and a “close” button.

The image in the post contains an anchor link to the dialog; the close button in the dialog links back to the image in the post.³ I wrap the lightbox image itself in a link to the full version of the image, which makes it easier for users to zoom in further using their browser’s own tools, if they like.

Even without CSS, this works (albeit with “scrolling” up and down to the larger image). But the clever bit’s yet to come:

The Style

body:has(dialog:target) {
  /* Prevent page scrolling when lightbox open (for browsers that support :has()) */
  position: fixed;
}

a[href^='#lightbox-'] {
  /* Show 'zoom in' cursor over lightboxed images. */
  cursor: zoom-in;
}

.lightbox {
  /* Lightboxes are hidden by-default, but occupy the full screen and top z-index layer when shown. */
  all: unset;
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 2;
  background: #333;
}

.lightbox:target {
  /* If the target of the URL points to the lightbox, it becomes visible. */
  display: flex;
}

.lightbox img {
  /* Images fill the lightbox. */
  object-fit: contain;
  height: 100%;
  width: 100%;
}

/* ... extra CSS for styling the close button etc. ... */

Here’s where the magic happens.

Lightboxes are hidden by default (display: none), but configured to fill the window when shown.

They’re shown by the selector .lightbox:target, which is triggered by the id of the <dialog> being referenced by the anchor part of the URL in your address bar!

Summary

It’s neither the most-elegant nor cleanest solution to the problem, but for me it hits a sweet spot between developer experience and user experience. I’m always disappointed when somebody’s “lightbox” requires some heavyweight third-party JavaScript (often loaded from a CDN), because that seems to be the epitome of the “take what the Web gives you for free, throw it away, and reimplement it badly in JavaScript” antipattern.

There’s things I’ve considered adding to my lightbox. Progressively-enhanced JavaScript that adds extra value and/or uses the Popover API where available, perhaps? View Transitions to animate the image “blowing up” to the larger size, while the full-size image loads in the background? Optimistic preloading when hovering over the image⁴? “Previous/next” image links when lightboxing a gallery? There’s lots of potential to expand it without breaking the core concept here.

I’d also like to take a deeper dive into the accessibility implications of this approach: I think it’s pretty good, but accessibility is a big topic and there’s always more to learn.

Close-up of a champagne-coloured French Bulldog wearing a teal jumper, lying in a basket and looking towards the camera. — In the meantime, why not try out my lightbox by clicking on this picture of my dog (photographed here staring longingly at the bacon sandwich picture above, perhaps).

I hope the idea’s of use to somebody else looking to achieve this kind of thing, too.

Footnotes

¹ Where JavaScript is absolutely necessary, I (a) host it on the same domain, for performance and privacy-respecting reasons, and (b) try to provide a functional alternative that doesn’t require JavaScript, ideally seamlessly.

² In practice, the lightbox images get lazy-loaded, so there can be a short round trip to fetch the image the first time. But after that, it’s instantaneous.

³ The pair – post image and lightbox image – work basically the same way as footnotes, like this one.

⁴ I already do this with links in general using the excellent instant.page.

Making WordPress Fast (The Hard Way)

This isn’t the guide for you

The Internet is full of guides on easily making your WordPress installation run fast. If you’re looking to speed up your WordPress site, you should go read those, not this.

Those guides often boil down to the same old tips:

uninstall unnecessary plugins,
optimise caching (both on the server and, via your headers, on clients/proxies),
resize your images properly and/or ensure WordPress is doing this for you,
use a CDN (and use DNS prefetch hints)¹,
tune your PHP installation so it’s got enough memory, keeps a process alive, etc.,
ensure your server is minifying² and compressing files, and
run it on a faster server/behind a faster connection³

You’ve heard those tips before, right? Today, let’s try something different.

The hard way

This article is for people who aren’t afraid to go tinkering in their WordPress codebase to squeeze a little extra (real world!) performance.

It’s for people whose neverending quest for perfection is already well beyond the point of diminishing returns.

But mostly, it’s for people who want to gawp at me, the freak who actually did this stuff just to make his personal blog a tiny bit nippier without spending an extra penny on hosting.

You shouldn’t use Lighthouse as your only measure of your site’s performance. But it’s still reassuring when you get to see those fireworks!

Don’t start with the hard way. Exhaust all the easy solutions – or at least, make a conscious effort which easy solutions to enact or reject – first. Only if you really want to get into the weeds should you actually try doing the things I propose here. They’re not for most sites, and they’re not the for faint of heart.

Performance is a tradeoff. Every performance improvement costs you something else: time, money, DX, UX, etc. What you choose to trade for performance gains depends on your priority of constituencies, which may differ from mine.⁴

This is not a recipe book. This won’t tell you what code to change or what commands to run. The right answers for your content will be different than the right answers for mine. Also: you shouldn’t change what you don’t understand! But I hope these tips will help you think about what questions you need to ask to make your site blazing fast.

Okay, let’s get started…

1. Backstab the plugins you can’t live without

If there are plugins you can’t remove because you depend upon their functionality, and those plugins inject content (especially JavaScript) on the front-end… backstab them to undermine that functionality.

For example, if you want Jetpack‘s backup and downtime monitoring features, but you don’t want it injecting random <link rel='stylesheet' id='...-jetpack-css' href='...' media='all' />‘s (an extra stylesheet to download and parse) into your pages: find the add_filter hook it uses and remove_filter it in your theme⁵.

Better yet, remove wp_head() from your theme entirely⁶. Now, instead of blocking the hooks you don’t want polluting your <head>, you’re specifically allowing only those you want. You’ll want to take care to get some semi-essential ones like <link rel="canonical" href="...">⁷.

Now most of your plugins are broken, but in exchange, your theme has reclaimed complete control over what gets sent to the user. You can select what content you actually want delivered, and deliver no more than that. It’s harder work for you, but your site becomes so much lighter.

Animated GIF from The Simpsons. Leonard Nimoy says "Well, my work is done here." Barney says "What do you mean? You didn't do anything?" Nimoy laughs and replies "Didn't I?" before disappearing as if transported away by a Star Trek teleporter. — Your site is faster now. It doesn’t work, but it’s quick about it!

2. Throw away 100% of your render-blocking JavaScript (and as much as you can of the rest)

The single biggest bottleneck to the user viewing a modern WordPress website is the JavaScript that needs to be downloaded, compiled, and executed before the page can be rendered. Most of that’s plugins, but even on a nearly-vanilla installation you might find a copy of jQuery (eww!) and some other files.

In step 1 you threw it all away, which is great… but I’m betting you were depending on some of that to make your site work? Let’s put it back, carefully and selectively, while minimising the impact on load time.

That means scripts should be loaded (a) low-down, and/or (b) marked defer (or, better yet, async), so they don’t block page rendering.

If you haven’t already, you might like to View Source on this page. Count my <script> tags. You’ll probably find just two of them: one external file marked async, and a second block right at the bottom.

The inline <script> in my footer.php wraps a single line of PHP: which looks a little like this: <?php echo implode("\n\n", apply_filters( 'danq_footer_js', [] ) ); ?>. For each item in an initially-empty array, it appends to the script tag. When I render anything that requires JavaScript, e.g. for 360° photography, I can just add to that (keyed, to prevent duplicates when viewing an archive page) array. Thus, the relevant script gets added exclusively to the pages where it’s needed, not to the entire site.

The only inline script added to every page loads my service worker, which itself aims to optimise caching as well as providing limited “offline” functionality.

While you’re tweaking your JavaScript anyway, you might like to check that any suitable addEventListeners are set to passive mode. Especially if you’re doing anything with touch or mousewheel events, you can often increase the perceived performance of these interactions by not letting your custom code block the default browser behaviour.

I promise you; most of your blog’s front-end JavaScript is either (a) garbage nobody wants, (b) polyfills for platforms nobody uses, or (c) huge libraries you’ve imported so you can use just one or two functions form them. Trash them.

3. Don’t use a CDN

Wait, what? That’s the opposite of what everybody else recommends. To understand why, you have to think about why people recommend a CDN in the first place. Their reasons are usually threefold:

Proximity
Claim: A CDN delivers content geographically-closer to the user.
Retort: Often true. But in step 4 we’re going to make sure that everything critical comes within the first TCP sliding window anyway, so there’s little benefit, and there’s a cost to that extra DNS lookup and fresh handshake. Edge caching your own content may have value, but for most sites it’ll have a much smaller impact than almost everything else on this list.
Precaching
Claim: A CDN improves the chance resources are precached in the user’s browser.
Retort: Possibly true, especially with fonts (although see step 6) but less than you’d think with JS libraries because there are so many different versions/hosts of each. Yours may well be the only site in the user’s circuit that uses a particular one!
Power
Claim: A CDN has more resources than you and so can better-withstand spikes of traffic.
Retort: Maybe, but they also introduce an additional single-point-of-failure. CDNs aren’t magically immune to downtime nor content-blocking, and if you depend on one you’ve just doubled the number of potential failure points that can make your site instantly useless. Furthermore: in exchange for those resources you’re trading away your users’ privacy and security: if a CDN gets hacked, every site that uses it gets hacked too.

Consider edge-caching your own content only if you think you need it, but ditch jsDeliver, cdnjs, Google Hosted Libraries etc.

Hell: if you can, ditch all JavaScript served from third-parties and slap a Content-Security-Policy: script-src 'self' header on your domain to dramatically reduce the entire attack surface of your site!⁸

4. Reduce your HTML and CSS size to <12kb compressed

There’s a magic number you need to know: 12kb. Because of some complicated but fascinating maths (and depending on how your hosting is configured), it can be significantly faster to initially load a web resource of up to 12kb than it is to load one of, say, 15kb. Also, for the same reason, loading a web resource of much less than 12kb might not be significantly faster than loading one only a little less than 12kb.

Exploit this by:

Making your pages as light as possible⁹, then
Inlining as much essential content as possible (CSS, SVGs, JavaScript etc.) to bring you back up to close-to that magic number again!

$ curl --compressed -so /dev/null -w "%{size_download}\n" https://danq.me/
              

              10416

Note that this is the compressed, over-the-wire size. Last I checked, my homepage weighed-in at about 10.4kb compressed, which includes the entirety of its HTML and CSS, most of its JS, and a couple of its SVG images.

Again, this probably flies in the face of everything you were taught about performance. I’m sure you were told that you should <link> to your stylesheets so that they can be cached across page loads. But it turns out that if you can make your HTML and CSS small enough, the opposite is true and you should inline the stylesheet again: caching styles becomes almost irrelevant if you get all the content in a single round-trip anyway!

For extra credit, consider optimising your homepage’s CSS so it’s even smaller by excluding directives that only apply to non-homepage pages, and vice-versa. Assuming you’re using a preprocessor, this shouldn’t be too hard: at simplest, you can have a homepage.css and main.css, each derived from a set of source files some of which they share (reset/normalisation, typography, colours, whatever) and the rest which is specific only to that part of the site.

Most web pages should fit entirely onto a floppy disk. This one doesn’t, mostly because of all the Simpsons clips, but most should.

Can’t manage to get your HTML and CSS down below the magic number? Then at least ensure that your HTML alone weighs in at <12kb compressed and you’ll still get some of the benefits. If you’ve got the headroom, you can selectively include a <style> block containing only the most-crucial CSS, with a particular focus on any that results in layout shifts (e.g. anything that specifies the height: of otherwise dynamically-sized block elements, or that declares an element position: absolute or position: fixed). These kinds of changes are relatively computationally-expensive because they cause content to re-flow, so provide hints as soon as possible so that the browser can accommodate for them.

5. Make the first load awesome

We don’t really talk about content being “above the fold” like we used to, because the modern Web has such a diverse array of screen sizes and resolutions that doing so doesn’t make much sense.

But if loading your full page is still going to take multiple HTTP requests (scripts, images, fonts, whatever), you should still try to deliver the maximum possible value in the first round-trip. That means:

Making sure all your textual content loads immediately! Unless you’re delivering a huge amount of text, there’s absolutely no excuse for lazy-loading text: it’s usually tiny, compresses well, and it’s fast to parse. It’s also the most-important content of most pages. Get it delivered to the browser so it can be rendered rightaway.
Lazy-loading images that are “expected” to be below the fold, using the proper HTML mechanism for this (never a JavaScript approach).
Reserving space for blocks by sizing images appropriately, e.g. using <img width="..." height="..." ...> or having them load as a background with background-size: cover or contain in a block sized with CSS delivered in the initial payload. This reduces layout shift, which mitigates the need for computationally-expensive content reflows.
If possible (see point 4), move vector images that support basic site functionality, like logos, inline. This might also apply to icons, if they’re “as important” as text content.
Marking everything up with standard semantic HTML. There’s a trend for component-driven design to go much too far, resulting in JavaScript components being used in place of standard elements like links, buttons, and images, resulting in highly-fragile websites: when those scripts fail (or are very slow to load), the page becomes unusable.

6. Reduce your dependence on downloaded fonts

Fonts are lovely and can be an important part of your brand identity, but they can also add a lot of weight to your web pages.

If you’re ready and able to drop your webfonts and appreciate the beauty and flexibility of a system font stack (I get it: I’m not there quite yet!), you can at least make smarter use of your fonts:

Every modern browser supports WOFF2, so you can ditch those chunky old formats you’re clinging onto.
If you’re only using the Latin alphabet, minify your fonts further by dropping the characters you don’t need: tools like Google Webfonts Helper can help with this, as well as making it easier to selfhost fonts from the most-popular library (is a smart idea for the reasons described under point 3, above!). There are tools available to further minify fonts if e.g. you only need the capital letters for your title font or something.
- - Browsers are pretty clever and will work-around it if you make a mistake. Didn’t include an emoji or some obscure mathematical symbol, and then accidentally used them in a post? Browsers will switch to a system font that can fill in the gap, for you.
Make the most-liberal use of the font-display: CSS directive that you can tolerate!
- Don’t use font-display: block, which is functionally the default in most browsers, unless you absolutely have to.
- font-display: fallback is good if you’re too cowardly/think your font is too important for you to try font-display: optional.
- font-display: optional is an excellent choice for body text: if the browser thinks it’s worthwhile to download the font (it might choose not to if the operating system indicates that it’s using a metered or low-bandwidth connection, for example), it’ll try to download it, but it won’t let doing so slow things down too much and it’ll fall-back to whatever backup (system) font you specify.
- font-display: swap is also worth considering: this will render any text immediately, even if the right font hasn’t downloaded yet, with no blocking time whatsoever, and then swap it for the right font when it appears. It’s probably better for headings, because large paragraphs of text can be a little disorienting if they change font while a user is looking at them!

If writing is for nerds, then typography must be doubly-so. But you’ve read this far, so I’m confident that you qualify…

7. Cache pre-compressed static files

It’s possible that by this point you’re saying “if I had to do this much work, I might as well just use a static site generator”. Well good news: that’s what you’re about to do!

Obviously you should make sure all your regular caching improvements (appropriate HTTP headers for caching, a service worker that further improves on that logic based on your content’s update schedule, etc.) first. Again: everything in this guide presupposes that you’ve already done the things that normal people do.

By aggressively caching pre-compressed copies of all your pages, you’re effectively getting the best of both worlds: a website that, for anonymous visitors, is served directly from .html.gz files on a hard disk or even straight from RAM in memcached¹⁰, but which still maintains all the necessary server-side interactivity to allow it to be used as a conventional Web-based CMS (including accepting comments if that’s your jam).

WP Super Cache can do the heavy lifting for you for a filesystem-based solution so long as you put it into “Expert” mode and amending your webserver configuration. I’m using Nginx, so I needed a try_files directive like this:

location / {
try_files /wp-content/cache/supercache/$http_host/$wp_super_cache_path/index-https.html $uri $uri/ /index.php?$args;
}

8. Optimise image formats

I’m sure your favourite performance testing tool has already complained at you about your failure to use the best formats possible when serving images to your users. But how can you fix it?

There are some great plugins for improving your images automatically and/or in bulk – I use EWWW Image Optimizer – but to really make the most of them you’ll want to reconfigure your webserver to detect clients that Accept: image/webp and attempt to dynamically serve them .webp variants, for example. Or if you’re ready to give up on legacy formats and replace all your .pngs with .webps, that’s probably fine too!

Image containing the text — The image you see at `https://danq.me/_q23u/2023/11/dynamic.png` is *probably* an `image/webp`. But if your browser doesn’t support WebP, you’ll get an `image/png` instead!

Assuming you’ve got curl and Imagemagick‘s identify, you can see this in action:

curl -s https://danq.me/_q23u/2023/11/dynamic.png -H "Accept: image/webp" | identify -
(Will give you a WebP image)
curl -s https://danq.me/_q23u/2023/11/dynamic.png -H "Accept: image/png" | identify -
(Will give you a PNG image, even though the URL is the same)

9. Simplify, simplify, simplify

The single biggest impact you can have upon the performance of your WordPress pages is to make them less complex.

I’m not necessarily saying that everybody should follow in my lead and co-publish their WordPress sites on the Gemini protocol. But you’ve got to admit: the simplicity of the Gemini protocol and the associated Gemtext format makes both lightning fast.

Writing my templates and posts so that they’re compatible with CapsulePress helps keep my code necessarily-simple. You don’t have to do that, though, but you should be asking yourself:

Does my DOM need to cascade so deeply? Could I achieve the same with less?
Am I pre-emptively creating content, e.g. adding a hidden <dialog> directly to the markup in the anticipation that it might be triggered later using JavaScript, rather than having that JavaScript run document.createElement the element after the page becomes readable?
Have I created unnecessarily-long chains of CSS selectors¹¹ when what I really want is a simple class name, or perhaps even a semantic element name?

10. Add a Service Worker

A service worker isn’t magic. In particular, it can’t help you with those new visitors hitting your site for the first time¹².

A service worker lets you do smart things on behalf of the user’s network connection, so that by the time they ask for a resource, you already fetched it for them.

But a suitable service worker can do a few things that can help with performance. In particular, you might consider:

Precaching assets that you anticipate they’re likely to need (e.g. if you use different stylesheets for the homepage and other pages, you can preload both so no matter where a user lands they’ve already got the CSS they’ll need for the entire site).
Preloading popular pages like the homepage and recent articles, allowing them to load quickly.
Caching a fallback pages – and other resources as-they’re-accessed – to support a full experience for users even if they (or your site!) disconnect from the Internet (or even embedding “save for offline” functionality!).

Chapters 7 and 8 of Going Offline by Jeremy Keith are especially good for explaining how this can be achieved, and it’s all much easier than everything else I just described.

Anything else?

Did I miss anything? If you’ve got a tip about ramping up WordPress performance that isn’t one of the “typical seven” – probably because it’s too hard to be worthwhile for most people – I’d love to hear it!

Footnotes

¹ You’ll sometimes see guides that suggest that using a CDN is to be recommended specifically because it splits your assets among multiple domains/subdomains, which mitigates browsers’ limitation on the number of files they can download simultaneously. This is terrible advice, because such limitations essentially don’t exist any more, but DNS lookups and TLS handshakes still have a bandwidth and computational cost. There are good things about CDNs, sometimes, but this has not been one of them for some time now.

² I’m not sure why guides keep stressing the importance of minifying code, because by the time you’re compressing them too it’s almost pointless. I guess it’s helpful if your compression fails?

³ “Use a faster server” is a “just throw money/the environment at it” solution. I’d like to think we can do better.

⁴ For my personal blog, I choose to prioritise user experience, privacy, accessibility, resilience, and standards compliance above almost everything else.

⁵ If you prefer to keep your backstab code separate, you can put it in a custom plugin, but you might find that you have to name it something late in the alphabet – I’ve previously used names like zzz-danq-anti-plugin-hacks – to ensure that they load after the plugins whose functionality you intend to unhook: broadly-speaking, WordPress loads plugins in alphabetical order.

⁶ I’ve assumed you’re using a classic, not block, theme. If you’re using a block theme, you get a whole different set of performance challenges to think about. Don’t get me wrong: I love block themes and think they’re a great way to put more people in control of their site’s design! But if you’re at the point where you’re comfortable digging this deep into your site’s PHP code, you probably don’t need that feature anyway, right?

⁷ WordPress is really good at serving functionally-duplicate content, so search engines appreciate it if you declare a proper canonical URL.

⁸ Before you choose to block all third-party JavaScript, you might have to whitelist Google Analytics if you’re the kind of person who doesn’t mind selling their visitor data to the world’s biggest harvester of personal information in exchange for some pretty graphs. I’m not that kind of person.

⁹ You were looking to join me in 512kb club anyway, right?

¹⁰ I’ve experimented with mounting a ramdisk and storing the WP Super Cache directory there, but it didn’t make a huge difference, probably because my files are so small that the parse/render time on the browser side dominates the total cascade, and they’re already being served from an SSD. I imagine in my case memcached would provide similarly-small benefits.

¹¹ I really love the power of CSS preprocessors like Sass, but they do make it deceptively easy to create many more – and longer – selectors than you intended in your final compiled stylesheet.

¹² Tools like Lighthouse usually simulate first-time visitors, which can be a little unfair to sites with great performance for established visitors. But everybody is a first-time visitor at least once (and probably more times, as caches expire or are cleared), so they’re still a metric you should consider.

CapsulePress – Gemini / Spartan / Gopher to WordPress bridge

For a while now, this site has been partially mirrored via the Gemini¹ and Gopher protocols.² Earlier this year I presented hacky versions of the tools I’d used to acieve this (and made people feel nostalgic).

Now I’ve added support for Spartan³ too and, seeing as the implementations shared functionality, I’ve combined all three – Gemini, Spartan, and Gopher – into a single package: CapsulePress.

CapsulePress is a Gemini/Spartan/Gopher to WordPress bridge. It lets you use WordPress as a CMS for any or all of those three non-Web protocols in addition to the Web.

For example, that means that this post is available on all of:

my weblog, at https://danq.me/2023/09/10/capsulepress‎,
my gemlog, at gemini://danq.me/posts/capsulepress,
my spartanlog, at spartan://danq.me/posts/capsulepress, and
my goperhole, at gopher://danq.me/1/posts/capsulepress

It’s also possible to write posts that selectively appear via different media: if I want to put something exclusively on my gemlog, I can, by assigning metadata that tells WordPress to suppress a post but still expose it to CapsulePress. Neat!

90s-style web banners in the style of Netscape ads, saying "Gemini now!", "Spartan now!", and "Gopher now!". Beneath then a wider banner ad promotes CapsulePress v0.1. — Using Gemini and friends in the 2020s make me feel like the dream of the Internet of the nineties and early-naughties is still alive. But with fewer banner ads.

I’ve open-sourced the whole thing under a super-permissive license, so if you want your own WordPress blog to “feed” your Gemlog… now you can. With a few caveats:

It’s hard to use. While not as hacky as the disparate piles of code it replaced, it’s still not the cleanest. To modify it you’ll need a basic comprehension of all three protocols, plus Ruby, SQL, and sysadmin skills.
It’s super opinionated. It’s very much geared towards my use case. It’s improved by the use of templates. but it’s still probably only suitable for this site for the time being, until you make changes.
It’s very-much unfinished. I’ve got a growing to-do list, which should be a good clue that it’s Not Finished. Maybe it never will but. But there’ll be changes yet to come.

Whether or not your WordPress blog makes the jump to Geminispace⁴, I hope you’ll came take a look at mine at one of the URLs linked above, and then continue to explore.

If you’re nostalgic for the interpersonal Internet – or just the idea of it, if you’re too young to remember it… you’ll find it there. (That Internet never actually went away, but it’s harder to find on today’s big Web than it is on lighter protocols.)

Footnotes

¹ Also available via Gemini.

² Also via Finger (but that’s another story).

³ Also available via Spartan.

⁴ Need a browser? I suggest Lagrange.

512kb.club

Proud to say that danq.me is the newest site to be admitted into Kev Quirk‘s 512kb club. Let’s keep the web lean!