Piper TTS is one of the most established open-source TTS engines, widely used in Home Assistant, accessibility tools, and edge computing projects. It uses the VITS neural architecture trained on the LibriTTS dataset.

The full dataset contains 904 distinct English voices. We curate 25 of the most distinct and useful speakers for the browser interface, ranging from warm narrators to professional presenters.

Piper is optimized for CPU inference via WebAssembly, generating audio 3-5x faster than realtime on standard hardware. It has a fixed 22.05kHz sample rate and runs without WebGPU — making it compatible with every modern browser.