Zyphra

Zyphra has open-sourced ZONOS3-Mini under Apache 2.0, a text-to-speech model built on a sparse Mixture-of-Experts design with 800M total parameters and roughly 100M active per token, paired with a new 15 Hz codec (ZAC-1) that cuts the number of frames to generate, enabling real-time operation on phones and laptops. On Zyphra's own ZTTS2-Eval it scores 66.2 on the Capability Index, ahead of Fish Audio S2 Pro (61.7) and MOSS-TTS v1.5 (60.2), with clean-set WER of 7.79 and 80 ms time to first audio on a single H100; reference-clip cloning, however, drops to 44.7 on the same index, and all results come from the vendor's own benchmark.