Chris Coyier

Howdy folks, co-founder of @CodePen here. 🤘 Why would you, fellow front-end designer & developer, want a CodePen account? Well it’s my job to make sure that has a clear answer, so I’m gonna thread 🧵 it up for ya to explore and understand.

New episode 👀 @ChrisCoyier joins @RobbyRussell to discuss maintaining CodePen for 15+ years, migrating from Rails to Go, and why maintainability is often more about people than code. Listen here: buff.ly/3bcbYhC

@SlexAxton 👀

trees.software <---

I worked a bunch on performance for trees, and I think the performance is really good actually, but I'm eager to get back in the lab and make this even better. This demo is entirely on the main thread. Seeded from a list of 1.5m presorted path strings in a javascript array. We can do a lot better than that!

What To Know in JavaScript (2026 Edition) An overview of what's new in language features, frameworks, runtimes, build tools, testing, and more. frontendmasters.com/blog/what-to-k…

For those curious, my challenge was to vertically center a title bar when buttons on either side could be of different widths. It's not perfect - Ellipses appear early - but it's good enough to ship. Pen: codepen.io/editor/bholmes…

@aaroniker @CodePen We do have a page about this: blog.codepen.io/documentation/…

and another one that just copied my code basically 1:1 Which is the copy? 🤔 (Links in comments) Is there any rule @CodePen @ChrisCoyier 🙂

I thought about things that have happened in CSS in 2025 and what I think you should probably know. Then I blogged it on @FrontendMasters. frontendmasters.com/blog/what-you-… It's not *everything* — it's my own curated list.

Gonna fiddle (on a stream) of making my own opinionated CSS reset. twitch.tv/chriscoyier

Gonna stream in a little bit. (Probably) looking at the neat new package support in the CodePen 2.0 (Private Beta) via import maps. twitch.tv/chriscoyier (I'm told a few minutes heads up is helpful.)

Scope in CSS We've got @scope in CSS now, and it's got it's uses. But the concept of scope in CSS is a wider idea. frontendmasters.com/blog/scope-in-…

✨ New article is live: CSS Spotlight Effect I asked myself what we could do with just the mouse position, and got to this fun simple effect. Hope you enjoy it, and maybe it will spark some new ideas for you too. 😊 🔗 Check it out on @FrontendMasters: frontendmasters.com/blog/css-spotl…

We’re working on something called Nested View Transition Groups … and we need your feedback! See the questions listed in the replies to this post: bsky.app/profile/martr.… Try it out in Chrome Canary + Exp Web Platform Features: codepen.io/bramus/full/og… #ViewTransitions #CSS

@appfactory shoot me an email? chriscoyier@gmail.com

Hey @chriscoyier! I building RedwoodSDK along with 3 other people. I saw you mentioned our new thing on your blog, I would be keen to tell you more about it

Giving anchor-tool.com a much-needed little facelift

@rook1e_stdout My feeds are open e.g. chriscoyier.net/feed/

@chriscoyier Would you be willing to share these feeds with us? I operate a search engine for personal websites, and we gather data from RSS feeds. rawweb.org

Who’s gonna read your personal blog because it has an RSS feed? I’m gonna read your personal blog because it has an RSS feed.

New Battle is LIVE on CSSBattle! ⚔️ 2 fun targets have unlocked for playing. 🎯 Anddd...this battle is sponsored by the awesome @CodePen + there is some sweet CodePen swag kit to be won! 🎁😱 All the best everyone for the battle!

Another (cool) demo where I am using the same technique. Demo: codepen.io/t_afif/full/Pw… via @CodePen The border will smoothly stop (always) at the same position on hover. #codepenchallenge

We're hiring! codepen.io/team/wtc/pen/q…

Relatively New Things You Should Know about HTML Heading Into 2025 Accordion details, toggle switches, styleable selects, responsive video, and more! frontendmasters.com/blog/bone-up-h…

I did some open-source this year! Here's a compilation of stuff I posted on @CodePen in 2024 All the live demos + source code: codepen.io/ksenia-k/pens/…

@AdamRackis @leojuriolli7 hopefully fixed

@leojuriolli7 @chriscoyier

I've been hyping TanStack Start long enough; it's time to show why I love it so much. Start took a superb client-first framework (Router) and added SSR in a non-obtrusive way. The react-query integration offers better component-level data fetching than RSC Link below 👇