Fish Audio

Fish Audio builds the text-to-speech models that quietly power voice features inside HeyGen, Retell, Sanas, and other AI products, and it also ships that same technology as a standalone playground and API. Its flagship model, S1, was trained on more than 2 million hours of audio and hits a 0.8% word error rate on the Seed TTS benchmark, with support for open-domain emotion and tone markers, cross-lingual speech, and voice cloning from as little as 10 to 30 seconds of reference audio with no separate training step. The API is pay-as-you-go from the first call, priced at $15 per million UTF-8 bytes of input text with no seat fees or minimum commitment, and a free-tier model variant exists for testing and prototyping without production guarantees. For teams that need to self-host, Fish Audio's core models ship as open weights under a paid commercial license, deployable in a private VPC, on-prem, or air-gapped environment. The consumer-facing playground adds credit-based subscription plans with unlimited public voice slots on every tier, making it accessible for solo creators as well as engineering teams shipping voice into their own product.