CodePen Radio

When we set out to build the 2.0 editor, another editor in the CodePen cannon, the goal was actually to reduce the number of editors we have and support. Ideally, reduce it to one. The trick is that anything an existing Pen or Project can do, this new editor needs to be able to do as well. All while making sure it's forever future extensible. That was the wild engineering task in front of us, and...

Marie has her eye on what seems to be super popular with CodePen users so far this year. Galleries (in different directions) https://codepen.io/thebabydino/pen/dPXVyqN https://codepen.io/luis-lessrain/pen/ZYpyoRV https://codepen.io/Nidal95/pen/qENQPBp https://codepen.io/ol-ivier/pen/emdjmBQ https://codepen.io/cbolson/pen/MYebgqj Custom Select https://codepen.io/editor/cbolson/pen/019cbfe5-85da-7d3...

Rachel and Chris on the podcast this week discussion the (ahem, rather large news) that every CodePen 2.0 Pen is versioned. That's right, you can jump back in time to previous versions at any time in case mistakes were made. You can take a look at the preview and code of past versions in case you just need to reference something. It all works extremely fast and efficiently. We get into the why and...

Shaw and Chris talk about how the keyboard shortcut situation is challenging, but in the best shape it's ever been in for our 2.0 editor. Between the operating system, browser, CodeMirror, and Emmet, the space is fairly crowded, but we've got enough room to offer lots of useful stuff. The commands are more findable than ever with our new Command system and the Omnibar. Time Jumps

We've had realtime features on CodePen for ages. Back when it was pretty damn hard. Our Collab Mode is an obvious one, where users can code together. (This "just works" in the 2.0 editor, it's not called anything special.) That and Professor Mode used to have realtime chat (until we pulled it because very few people used it). We went through iterations of this including our own implementations and...

Rachel and Chris on the show this week to discuss a series of big changes over the last, say, six months or so with our billing system. We've essentially re-written this thing several times, and obviously this is the best time. Having three plans, two payment providers, teams, and fifteen years of history is a lot to manage. An important aspect of the journey was getting the billing information in...

Having that first response from the server to users browsers be, ya know, full of good, useful, renderable HTML is certainly better than an empty <div id="app">. You can feel it and see it in the filmstrip view of the site loading. Not to mention you need it for at least things like <meta> tags if you want your URLs to "unfurl" properly on social sites. Stephen and Chris jump on the po...

Stephen and Chris chat about how the 2.0 editor (well, the compiler really) understands and supports Browserslist , a config format that lives in your package.json file that multiple blocks can understand and make browser support decisions against. Sponsor: Notion With the recent launch of Custom Agents, Notion became the collaborative AI workspace where teams and agents work side by side. And now...

As we're getting close to rounding out the Beta period of the 2.0 editor, we're trying to close out any bugs we find or users report quickly. They could be browser-support related, network conditions related, account capability related, or just bugs in how the 2.0 editor and technology behind it works. It's complicated enough that the best way to debug things is to see exactly what the user sees w...

The 2.0 Editor can support hundreds of files per Pen, not to mention folders mixed in which don't count toward that total. This can be pretty weighty on the DOM and thus adversely affect performance. Especially as each file/folder has children, a variety of event listeners, are drag and drop enabled, etc. "Virtualizing" data like this is a common approach, but we've found if we just use Intersecti...

Stephen and Chris hop on the ol' podcast to talk about all the ways that Templates are way better in 2.0 land. You've always been able to make your own templates, but now you can select one even after you've arrived in the editor. There is a new place ( the create page ) which features bookmarked and official templates (as well as your own). Most importantly, there is a way to set a "default templ...

Alex and Chris talk about how the 2.0 Editor supports packages from npm . The trick is both simple and complex. The idea is simple. We detect the packages you want to use, list them in an (editable) package.json file, then turn that into a <script type="importmap"> in your HTML files that import those packages from esm.sh . Complex in that, well, all those steps are fairly difficult to get righ...

Stephen & Chris look at the UI of the 2.0 Editor and show all the control you have over what you're looking at. Way more control than the Classic editor! We share some of the thinking behind it. Don't miss the Omnibar! Time Jumps Links Circle Round Story Pirates Podcast Who Moved My Cheese? The freeCodeCamp Podcast

With CodePen 2.0, we've got a new word we're using: Blocks . A way to think about Blocks is anything that processes code. They are added as steps to the CodePen Compiler as needed. For example, TypeScript is a block, because it processes files in the TypeScript syntax into JavaScript files. But something like Lodash is not a block. Lodash is a package from npm (which we also handle , but that's a...

CodePen 2.0 was the most ambitious project that we've ever taken on in our lives. Why would we do such a thing? Chris and Alex explain the thinking behind it. We've been around a long time, know what our customers want, and are developers ourselves, so we know how this industry moves. We thought we could serve both in a powerful and flexible way, taking us into the future. Time Jumps

Chris Coyier and Stephen Shaw discuss the transition from CodeMirror 5 to CodeMirror 6 , highlighting the significant improvements in accessibility, performance, and user experience. They delve into architectural changes, integration with modern JavaScript frameworks such as Next.js, and the new theming options available in the editor. Time Jumps

There was a day not long ago where a Google Chrome browser update left any page with a CodePen Embed on it throwing a whole big pile of red JavaScript errors in the console. Not ideal, obviously. The change was related to how the browser handles allow attributes on iframes (i.e. <iframe allow="...">). CodePen was calculating the appropriate values inside an iframe for a nested iframe. That m...

Shaw and Chris are on the show to talk about the thinking and challenges behind upgrading these rather important bits of technology in our stack. We definitely think of React version upgrades and Next.js version upgrades as different things. Sometimes they are prerequisites. The Next.js ones are a bit more important as 1) the docs for the most recent version tend to be the best and 2) it involves...

Robert and Chris hop on the show to talk about choices we've had to make around Babel . Probably the best way to use Babel is to just use the @babel/preset-env plugin so you get modern JavaScript features processed down to a level of browser support you find comfortable. But Babel supports all sorts of plugins, and in our Classic Editor, all you do is select "Babel" from a dropdown menu and that's...

Rachel and Chris jump on the show to talk about a bit of client-side technology we use: Apollo . We use it because we have a GraphQL API and Apollo helps us write queries and mutations that go through that API. It slots in quite nicely with our React front-end, providing hooks we use to do the data work we need to do when we need to do it. Plus we get typed data all the way through. Chris gets to...

We're over 13 years old as a company now. We decide that we're not a startup anymore (we're a "small business" with big dreams) but we are still indie. We've seen trends come and go. We just do what we do, knowing the tradeoffs, and plan to keep getting better as long as we can. Links Timeline – Chris Coyier 115: Adam Argyle on Cracking the 2025 Web Dev Interview | Front-End Fire Time Jumps

Or just "Embeds" as we more frequently refer to them as. Stephen and Chris talk about the fairly meaty project which was re-writing our Embeds for a CodePen 2.0 world. No longer can we assume Pens are just one HTML, CSS, and JavaScript "file", so they needed a bit of a redesign, but doing as little as possible so that existing Embed Themes still work. This was plenty tricky as it was a re-write fr...

Alex and Chris hop on the show to talk about a bit of technology that Alex calls "The 2nd best technological choice he's ever made." That technology is called Tree-sitter . It's a code parsing tool for building ASTs (Abstract Syntax Trees) out of code. GitHub uses it to power search and "go to" functionality. The creators now work on Zen , where a code parser is paramount. We use it to understand...

Chris & Marie jump on the podcast to talk about just how drastically customer support has changed over the last few years. We still exclusively do customer support over email. Incoming email from real customers who need a hand with something where they type out that email in plain languages themselves are few and far between. Instead we get an onslaught of noise from users that don't exist abo...

Chris and Stephen talk about how we use a Cloudflare Worker & HTMLRewriter to inject a very special <script> tag into the previews of the Pens you work on. This script has a lot of important jobs so it's presence is crucial, and getting it in there reliably can is a bit of a challenge. Time Jumps