Client-Side ASR (Whisper In The Browser) Engineering Cheat Sheet

One-page reference: the name untangle ('faster-whisper' is a server-side CTranslate2 library, NOT a browser engine; the real browser engines are whisper.cpp via WebAssembly and Transformers.js via WebGPU; plus the built-in Web Speech API, which sends audio to Google by default); the in-browser pipeline (microphone -> 16 kHz mono -> Silero VAD gate -> Whisper -> caption, all in the tab); WebAssembly-vs-WebGPU (CPU vs GPU, ~100x, cross-origin isolation COOP+COEP for Wasm threads); the cost ledger (model download 31-182 MB quantized, memory, battery); the real-time-factor check (RTF below 1.0 keeps up live); Moonshine for tight live loops; and the client-vs-server decision table.