Very cool that random() in CSS is coming to Chrome to join Safari who led that feature. It means one of my favorite demos I’ve made when I was first playing with it will work for more people. I just like how little code it is and how it combines some fun modern CSS features.

I had blogged that demo here among some other demos. Some other folks are blogging about it too, like Kilian’s experimenting with the new pure CSS random() function and Alvaro’s The Importance of Native Randomness in CSS. I like how Alvaro paints a picture of a very paved cow path. Meaning we’ve been kinda faking randomness for a long time, and all of that kinda sucked. Real randomness in CSS is very welcome and the API is… pretty good. More well thought out than I could have come up with, which feels like the CSS WG are on their game here.

For the first time, CSS can model natural systems with variation directly: no hacks, no tools, no outsourcing layout decisions to other languages. Randomization takes an honored place in the styling layer, where it always belonged.

This embettering of CSS has me thinking about other things that just get a little bit better as time and effort march on. Like how all the sudden 100vw didn’t mess with scrollbars anymore. That’s just nice. And now we can style the gaps in grid/flexbox/columns without needing any tricks or extra markup to do it. Fantastic, gang, keep on keeping on.

It works that way in software too. Like, I see HTMX just went to 4.0. Good job, team! Seems like a nice release. It’s clear that some folks have a great experience building lightweight, fast apps with HTMX.

CodePen itself gets better all the time, too. I mean, we literally have a team that works every day doing that, in case that wasn’t obvious. We’re coming out of a super-long period getting 2.0 out the door where y’all probably didn’t see much happening, but now we’re shipping user-facing stuff much faster!

We’ve been posting CHANGELOGs in the Discord lately. You should join!

Changelog 2026/09/03: New Blocks, draggable panels, improved performance, and fixed pagination.

I’ll post that, and the next one, as regular text here:

CHANGELOG 2026/09/03

  • New Blocks! TypeScript 7, Jest, Mermaid, MJML, and…. Svelte ???
  • Draggable Panels! If you’ve ever wanted to see Files and Build Status at the same time or needed a bit more space for the Details.
  • Increased performance in the Editor and across the whole site.
  • Fixed pagination, so you shouldn’t be missing any items as you page around.

CHANGELOG 2026/09/11

  • CodePen API for PROs! V1 is read-only and just Classic Pens for now. We’re already in the works for V2 that is far more robust, so if there are any use case requests, please let us know.
  • Faster, easier file uploads in Pens & Assets.
  • Larger file sizes for Developer PRO (20 MB) & Super PRO (30 MB)
  • Increased Asset storage for Developer PRO (25 GB) and Super PRO (50 GB)
  • Prettier support for Svelte, MJML, GLSL and more.
  • Increased site speed (Updated Databases & Servers, Smaller Bundles, less Cloudflare interruptions)
  • Updated the screenshot engine to use the latest Chrome.
  • More accessible Default Pen.
  • Omnibar shortcuts to open panels as tabs, or double-click sidebar icons to open as a tab.
  • .ps1 and .liquid files are allowed in the Editor (with syntax highlighting), but they’re currently not processed.