The “My Checks” page on Healthchecks shows integration icons next to each check. Users can click the integrations to toggle them on and off: I added this feature in June 2018. Before then, the Integrations column was simply absent. My initial implementation used PNG images to display the integration icons, each icon being a separate `<img>` element in HTML. This was a nice usability improvement, but created a performance problem: the browser stuggled to display and repaint the “My Checks” page for accounts with many checks. I solved the performance problem by putting the integration icons in an icon font and using it instead of many small PNG images. This worked wonderfully–there was no more stutter, even when listing hundreds of checks. Browsers are really efficient at displaying text, who knew! I was using icomoon.io for manipulating the icon font. It lets you assemble a set of icons, either by selecting from icon libraries or by uploading your own SVGs. You can manipulate each glyph, and you can export the font as .ttf, .woff, etc. files. IcoMoon’s UI is quirky, but the end results are good. Icon fonts created with IcoMoon can handle icons with multiple colors, but they work best with monochrome icons. The more colors an icon uses, the more HTML elements you have to use to display it: That is, until December 2025, when IcoMoon launched a beta of the new version of their app, which supports multicolor fonts! This allows simple HTML markup even for multicolor icons: <span class="ic-slack"></span> Moreover, the new version supports ligatures. Ligatures are conventionally used for joining multiple characters in one shape. For example, for displaying “oe” as “œ” or, in programming fonts, displaying “!=” as “≠”. In icon fonts, ligatures can be used to display a string of characters as a specific icon. This allows for even neater HTML markup: <span class="ic">slack</span> I have now updated Healthchecks to use multicolor icon fonts produced by IcoMoon’s new app, and I updated the Slack integration icon to take advantage of it (before on the left, after on the right): Happy pixel-pushing, Pēteris

Over the last few weeks, I indulged myself in doing a few “nice to have” website optimizations. They were: ### Upgrade to HAProxy 3.2 and Enable HTTP/3 I recently learned that HAProxy now provides first-party Debian and Ubuntu packages. Notably, these packages are not built with the OpenSSL library, but with the faster AWS-LC. And they support HTTP/3 out of the box. Up until now, I was using HAProxy packages from the vbernat PPA, which has only limited HTTP/3 support. Over the holiday season, I tested the AWS-LC packages with our specific HAProxy configuration (testssl.ssh was super handy here), and this week I deployed the changes to Healthchecks.io’s production load balancers and enabled HTTP/3. ### WordPress Theme for blog.healthchecks.io blog.healthchecks.io is a WordPress blog exported to a static site. I’m using the excellent HardyPress for managing it. The WordPress theme I had originally picked for the site was Astra. It is a relatively lightweight theme, but still has some superfluous HTML, JS, and CSS, which was bugging me to no end. During the holidays, I bit the bullet and put together a custom theme. I used the BlankSlate theme and the mvp.css stylesheet as the starting point, deleted large parts from both, and then edited the HTML markup and CSS to get the look right. Now the site looks better than before, has cleaner markup, a single CSS include, and no JS includes. Phew! ### WebP for the Landing Page Graphics I wanted to submit Healthchecks.io to 512kb.club, but the uncompressed size of the landing page was _a little_ over the required 512kB size limit. It was only a few kilobytes over, but the low-hanging fruit optimizations were already done (or so I thought). However, I did find one unoptimized PNG image, optimized it with oxipng, and got the page just below the limit. It later occurred to me that the size of the product illustrations (each a 30kB to 50kB PNG) could perhaps be reduced by converting to lossless WebP. Indeed, there was 30% – 50% space saving for each illustration, and the page now sits at 441kB uncompressed. And it looks the same in browsers, tested in Firefox, Chrome, _and_ Ladybird. Thanks for reading, and happy 2026, –Pēteris

In the age of artificial intelligence, we often compare humans and computers, asking ourselves which is “better”. But is this even the right question? The case of Air France Flight 447 suggests it isn't - and that the consequences of asking the wrong question are disastrous.

I’m experimenting with HTTP/3 on Ubuntu 24.04 and HAProxy 3.2 from the official -awslc packages: Download the Official HAProxy Performance Packages and got it working. I didn’t need to add AmbientCapabilities=CAP_NET_BIND_SERVICE in the service file but did need to add setcap cap_net_bind_service under the “global” section in haproxy.cfg. AIUI it passes the capability to the non-root user when it switches from root to non-root user. Another, unrelated gotcha I ran into was with incorrect alpn ...