- Runs inYour browser, via WebAssembly
- PrivacyYour code never leaves the browser
- LicenseOpen source, free
raku.online is a Raku playground that runs entirely in the browser. The interpreter is Raku++, our C++ implementation of Raku, compiled to WebAssembly as Raku.js. No code is ever sent to a server: your program executes in a Web Worker on your own machine, and the site itself is just five static files.
A program loaded in the playground — code on the left, its output on the right, running entirely in your browser.
What you can do
- Write and run Raku instantly. Type a program, press Run, and see the output — locally, offline once the page has loaded, with a Stop button that actually stops.
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Feed it input. A collapsible Stdin strip under the editor supplies standard input (
get,lines,prompt,$*IN), fresh on every run. - Share by link. The 🔗 Share button packs your code straight into the URL (deflate-compressed, base64url) — nothing is stored server-side — and anyone who opens the link gets your exact program, ready to run.
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Open code from anywhere. Load a program from a GitHub gist, a file in a GitHub repo, or any HTTPS URL that allows cross-origin fetches; append
&run=1to run it on load.
Embed runnable Raku on your own site
The same engine ships as a drop-in widget, raku.js. Add one script tag, and any code block you mark becomes a live, editable, runnable editor:
<script src="https://raku.online/raku.js"></script>
<pre data-raku>say "Hello from an embedded editor!";</pre>- Safe on any page. Each editor lives in its own Shadow DOM, so the host site's styles and the widget's styles never collide.
- Efficient. Every editor on a page shares a single Web Worker and one WebAssembly instance, so ten code blocks download the interpreter only once.
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No hand-written HTML needed. With
data-auto, ordinary highlightedrakucode blocks become runnable automatically, and the embed builder turns pasted code into a ready-to-paste snippet with a live preview.
The same widget in the wild — runnable code blocks embedded throughout spec.raku.online.
Open source
The site is a handful of static files served by nginx, and it is open source: github.com/ash/raku.online. Because it is self-contained, you can host the whole playground on any static server, or embed pieces of it anywhere you write about Raku.
Learning Raku?
raku.online is the fastest way to try the language, and it powers the instant playground of the Raku Course — our free online course of Raku, where every example can be edited and executed right on the page.