Hertz is a high-fidelity client-side audio processing engine.

https://github.com/askpext/HERTZ

'HERTZ is a web-based Digital Audio Workstation (DAW) utility designed for instant vocal polishing. It leverages the Web Audio API for real-time signal processing and FFmpeg.wasm for client-side encoding. Unlike traditional tools that rely on server-side processing (FFmpeg binaries on Linux), HERTZ runs entirely within the user's browser thread via WebAssembly.'