Fish Audio text-to-speech and voice cloning

Fish Audio is a TTS and voice-cloning provider with two distinct product surfaces that share a lineage but differ in licensing and operation:

1. Hosted API (api.fish.audio) — the commercial service. Current lineup is branded S2.1-Pro / S2-Pro / S1. Paid per UTF-8 byte, streaming, cloning, and a free tier.
2. Open weights — released under the OpenAudio brand (and earlier as Fish-Speech). Downloadable from Hugging Face and GitHub for self-hosting.

The single most important fact to get right: the hosted API and the open weights are not the same models, and their licenses differ. The full flagship weights are hosted-only; only smaller distilled weights are openly published, and those carry a non-commercial license. Never assume "Fish is open source, so I can self-host it commercially" — verify which artifact and which license apply. See Open weights and self-hosting below.

All model names, prices, endpoints, and limits below are volatile. Verification date for every dated claim in this document: 2026-07-10. Re-verify against docs.fish.audio before quoting these to a user as current.

Labels used throughout:

• [Doc] — stated in official Fish Audio / OpenAudio documentation, model cards, or their published technical reports.
• [Claim] — a first-party marketing or benchmark claim from Fish Audio/OpenAudio; treat as their assertion, not independently established.
• [Heuristic] — a production judgment from practice, not a documented guarantee.

When to use Fish Audio (and when not to)