Firefox in WebAssembly
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This is the entire Firefox browser rendering to a <canvas> element. Gecko, all UI components, and the Spidermonkey JS engine are all compiled and running in WebAssembly.Here are a few things you might find interesting:- This is fully end to end encrypted! We use the WISP protocol for TCP-over-websockets.- There is a novel WASM->JS JIT for experimental site speedup- This port cost over 25k in opus/fable tokens for debugging and JIT researchThis was just a fun experiment to push the boundaries of WebAssembly. For a more usable "browser in browser" experience, we also built https://github.com/HeyPuter/browser.js that eats a bit less RAM.
HN · launched Jul 15, 2026 · 273 upvotes (top 2%) · 3 views
Niche: specialized and developer web browsers · 83 launches, 9 in the last 7 days · Explore this niche →
Category and tags
- Horizontal
- Dev tools
- Developer
- Not AI
- Hobby / open-source project
Visit website ↗ Source listing ↗
More like this: all 83 launches in specialized and developer web browsers →
Could you build this?
No Porting the massive C++/Rust Firefox codebase, Gecko rendering engine, SpiderMonkey JS runtime, and sandboxed networking protocols to WebAssembly requires deep low-level compiler and browser engine internals expertise.
What it would actually take: This requires patching and compiling millions of lines of Mozilla C/C++ and Rust codebase via Emscripten and LLVM toolchains to targeting WASM/WASI. It entails implementing custom POSIX shims, creating an off-screen Skia/OpenGL surface mapped to HTML5 Canvas via WebGL, and architecting a WebSocket-based TCP emulation layer (WISP protocol proxy) for sandboxed web networking. This demands deep systems programming expertise in browser engines and WebAssembly runtime architecture.
Discussion
20 comments analyzed.
Competitors mentioned: libcurl.js (HTTPS proxy alternative), FreeCad WASM port
Concerns raised: WebGL/color rendering issues (ocean appearing pink instead of blue), Doesn't work on all websites normally, GPU driver quality significantly impacts performance across platforms, High server infrastructure costs (25k tokens, bandwidth saturation), Security model requires trusting intermediary with password access
Feature requests: Support for Apple Retina display, Browser compatibility check before large download, Better GPU driver support for Apple M5/Tahoe and Pixel 10 Pro, Improved TCP packet handling performance
Competitors
Other products that read as similar to this one : 333 launches clear the similarity bar, closest 8 shown.
Attention rank: #8 of 334 (itself plus its competitors, highest first, normalized so YC and Product Hunt are compared fairly).
Launched 259 days after the earliest competitor.
- Codex CLI compiled to WASM running in the browser · hn · 2026-08-19 · 5 upvotes · similarity 0.54
- Filenymous · ph · 2026-10-22 · 2 upvotes · similarity 0.49
- Waputer · hn · 2026-04-17 · 7 upvotes · similarity 0.49
- BrowserCode · hn · 2026-05-07 · 6 upvotes · similarity 0.48
- FFmpeg WebCLI · hn · 2026-06-04 · 86 upvotes · similarity 0.46
- Sandboxing untrusted code using WebAssembly · hn · 2026-02-03 · 76 upvotes · similarity 0.45
- JavaScript web apps with WASM layout and GPU rendering in 280 KB · hn · 2026-11-07 · 46 upvotes · similarity 0.45
- Node.JS in the Browser · hn · 2026-08-06 · 6 upvotes · similarity 0.45
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