Puter has successfully compiled the Firefox browser into WebAssembly (WASM), allowing the browser to run entirely within another web browser environment. The project leverages the Firefox/Gecko engine due to its robust single-process support. During development, the team utilized an estimated $25,000 worth of Claude Opus and Fable tokens, though actual costs were mitigated by using a Claude Max subscription plan.

To operate within a browser's security constraints, the demo routes all network traffic over WebSockets using the Wisp protocol through Puter’s servers. This server-side proxying requirement led to increased demand on the team's infrastructure, necessitating server scaling during the surge of user traffic following its debut on Hacker News. Puter maintains that the implementation supports end-to-end encryption; testing confirms that traffic to HTTPS sites remains encrypted, while cleartext is used for HTTP sites like http://www.example.com/. A similar project, theogbob/WebkitWasm, also exists for WebKit but lacks a live online demo.

Puter has successfully compiled the Firefox browser into WebAssembly (WASM), allowing the browser to run entirely within another web browser environment. The project leverages the Firefox/Gecko engine due to its robust single-process support. During development, the team utilized an estimated $25,000 worth of Claude Opus and Fable tokens, though actual costs were mitigated by using a Claude Max subscription plan.

To operate within a browser's security constraints, the demo routes all network traffic over WebSockets using the Wisp protocol through Puter’s servers. This server-side proxying requirement led to increased demand on the team's infrastructure, necessitating server scaling during the surge of user traffic following its debut on Hacker News. Puter maintains that the implementation supports end-to-end encryption; testing confirms that traffic to HTTPS sites remains encrypted, while cleartext is used for HTTP sites like http://www.example.com/. A similar project, theogbob/WebkitWasm, also exists for WebKit but lacks a live online demo.