BrowserPod: WebAssembly in-browser code sandboxes for Node, Python, and Rails

We’re launching BrowserPod today in open beta, after a month-long closed beta with early adopters.

BrowserPod is an in-browser code sandbox for dev environments built on WebAssembly, that runs Node.js directly in the browser with no cloud provisioning.

BrowserPod containers run Node.js code at native speed, without modifications, using only client-side compute. They are built on a full version of Node compiled to WebAssembly, with the browser’s local JavaScript engine taking the place of Node’s embedded v8. BrowserPod provides a Linux-compatible kernel built on top of WebAssembly and modern Web technologies. The BrowserPod kernel is derived from our previous work on x86 virtualization in the browser (see WebVM - https://webvm.io) and supports multiple processes/threads on top of WebWorkers and advanced filesystem and networking capabilities.

BrowserPod can seamlessly expose virtualized HTTP endpoints to the wider internet. We call this feature “Portals”. We believe Portals to be one of the most exciting features of BrowserPod, making it possible to run tests on real mobile devices or to share your work with testers, early adopters and customers without setting up any hosting.

While we’re focusing on Node.js 22 now, the architecture is language-agnostic. Python and Ruby support are immediate priorities and will be released in early 2026. Extensive support for command line tooling will be added in the near future. We’re prioritizing git, bash, and compression utilities, but let us know what tools would be most helpful for you.

I’d love to hear your thoughts, and I’m happy to take any technical questions you have.