WASM isn't even ready for day-to-day use yet, and while ASM.js is mature, V8 has no special optimisations for it. Furthermore, you're still running the code on

WASM isn't even ready for day-to-day use yet, and while ASM.js is mature, V8 has no special optimisations for it. Furthermore, you're still running the code on the Javascript VM/interpreter, so it's unlikely to give much of a speed boost. The motivation behind WASM and ASM.js both is to cross-compile code from other non-JS languages (generally, C/C++) into code usable from JS.