Run AI coding CLIs and frameworks in the browser

BrowserCode is a browser-based playground for fast-prototyping full-stack apps and sharing them instantly. It runs on BrowserPod, a multi-language WebAssembly sandbox (Node.js, Rust, and Python in preview), with no installs, no servers, and no cloud compute.

What is BrowserCode?
Quickstart
Make it your own
Embedding
Breaking BrowserCode
Roadmap

What is BrowserCode?

BrowserCode is a browser-based coding sandbox. It's a working example of BrowserPod, and includes:

Node.js v22, Rust and Python (preview) running in the browser via WebAssembly (more runtimes coming)
A browser-contained, POSIX-like filesystem
Command line tools: bash, git, npm
Browser sandbox isolation from the user's operating system
Restricted outbound networking: the npm and yarn registries, GitHub, and the major AI provider APIs are reachable by default
Instant previews over URL via BrowserPod's portal function
Support for Express.js, Svelte, Next, Nuxt and React (with Wasm overrides)

BrowserCode started out as a way to run AI coding CLIs entirely client-side. It's since grown into a full IDE: alongside the CLIs, it can boot and preview web frameworks directly in the browser, so you can prototype an agent's output without ever leaving the tab.

BrowserCode 1.1.0 is our latest beta release. It runs a full code editor, development environment, and unmodified versions of Claude Code and Codex CLI, completely client-side.

Quickstart

Want to try BrowserCode without installing anything? Use the hosted app.

Go to browsercode.io
BrowserCode will boot instantly, opening with a quick modal tutorial to guide you
Pick an agent from the sidebar, or open the IDE playground to boot a framework template
Claude Code signs in by copying a code from a separate tab; Codex CLI asks for an OpenAI API key, stored in your browser

Make it your own

Want to run your own copy, customize the CLIs, or contribute? Clone the repo and run it locally.

Clone the repository and install dependencies

git clone https://github.com/leaningtech/browsercode.git
cd browsercode
npm install

Get a BrowserPod API key at browserpod.io and expose it to the app as VITE_API_KEY
```
echo "VITE_API_KEY=your-key-here" > .env
```
Start the dev server
```
npm run dev
```
Open the printed local URL in a Chromium-based browser

Other useful scripts:

npm run build — build a production bundle
npm run preview — preview the production build locally
npm run check — type-check the project
npm run lint / npm run format — lint and format with Prettier + ESLint

CLI availability and behavior are configured in src/lib/config/tools.ts — this is the place to start if you want to add or tweak a CLI.

Embedding

BrowserCode can run inside another site's page through /embed, composed entirely from the query string.

<iframe
	src="https://browsercode.io/embed?framework=vite&view=preview"
	allow="cross-origin-isolated"
	style="width: 100%; height: 600px; border: 0"
></iframe>

BrowserPod needs SharedArrayBuffer, so the embedding page must send Cross-Origin-Opener-Policy: same-origin and Cross-Origin-Embedder-Policy: require-corp, and the iframe must carry allow="cross-origin-isolated".

Parameters, panes and further detail are in docs/embedding.md.

Breaking BrowserCode

This is BrowserCode beta. Don't be kind to it. Stretch it, bend it, find out what breaks. Here are a few walls you might hit:

At launch, each agent is given an instructions file (CLAUDE.md for Claude Code, AGENTS.md for Codex CLI) so it understands it is running in a custom environment. However, it may first attempt its default behavior before referencing the file
BrowserCode doesn't yet support native binaries. For more information, see the BrowserPod documentation
Networking over TCP isn't available
For maximum compatibility, please use a Chromium browser. Safari currently isn't supported