Firefox in WebAssembly This is absurdly cool: Puter compiled Firefox to WebAssembly such that the whole browser runs in another browser. Here's my blog, running in Firefox, running in WebAssembly, running in Chrome: They chose Firefox/Gecko because it has strong single-process support. The project took an estimated $25,000 of Claude Opus and Fable tokens, taking advantage of a Claude Max subscription plan. The demo funnels all traffic over a WebSocket protocol (using the Wisp protocol) throu ✦ AI generated
The porting effort relied heavily on AI assistance, consuming an estimated $25,000 in Claude Opus and Fable token usage, made affordable via a Claude Max subscription.
Simon Willison: The project took an estimated $25,000 of Claude Opus and Fable tokens, taking advantage of a Claude Max subscription plan.
gives example · 1
The team selected Firefox's Gecko engine specifically for its strong single-process support, which made it a better fit for compiling to WebAssembly.
Simon Willison: They chose Firefox/Gecko because it has strong single-process support. The project took an estimated $25,000 of Claude Opus and Fable tokens, taking advantage of a Claude Max subscription plan.
Puter built a project that compiles Firefox itself to WebAssembly, allowing the full browser to run inside another browser like Chrome.
Simon Willison: This is absurdly cool: Puter compiled Firefox to WebAssembly such that the whole browser runs in another browser. Here's my blog, running in Firefox, running in WebAssembly, running in Chrome
explains mechanism · 1extends · 1provides context · 1
The author independently verified Puter's claim of end-to-end encryption by inspecting WebSocket messages, finding HTTPS traffic encrypted and HTTP traffic sent in cleartext, confirming the claim held up.
Simon Willison: Puter claim this supports end-to-end encryption and that looks to be true - I inspected the WebSocket messages and traffic to my own HTTPS site was encrypted whereas requests and responses to http://www.example.com/ were in cleartext.
Because browser sandboxing prevents arbitrary outbound connections, the demo tunnels all of Firefox's network traffic through Puter's own server using the WebSocket-based Wisp protocol.
Simon Willison: The demo funnels all traffic over a WebSocket protocol (using the Wisp protocol) through Puter's server - a requirement to get this kind of thing to work because code running in browsers can't open arbitrary network connections.
Routing all browser traffic through a central proxy is costly, and Puter had to scale up its infrastructure to survive the surge in visitors after the project hit Hacker News.
Simon Willison: That proxying sounds expensive! The team had to scale the servers up to handle the traffic during the Hacker News conversation about the project.