Supertonic TTS: The Lightning-Fast On-Device Text-to-Speech Revolution in 2025

Supertonic: The Lightning-Fast, Fully On-Device TTS That Actually Works in 2025 Core Question: What exactly is Supertonic, and why is it running 100–167× faster than real-time on a laptop or phone — completely offline? Supertonic is a 66-million-parameter text-to-speech (TTS) model released by Supertone in 2025. Built for extreme on-device performance and powered by ONNX Runtime, it runs 100% locally on everything from smartphones to browsers — no cloud, no API keys, no privacy trade-offs. With just 2 inference steps it already sounds production-ready, and on Apple M4 Pro it hits an insane 167× real-time speed. Why Supertonic Changes Everything: …