Fish Audio announced that its S2.1 Pro text‑to‑speech model is now free for developers, reachable by setting the model parameter to "s2.1-pro-free". The model supports 83 languages, uses the same endpoint as the paid tier, and has no hard usage cap.
Switching to the free model
If you already call the Fish Audio API, the change is a one‑line config update: model: "s2.1-pro-free". No code refactor or new credentials are required, which keeps deployment pipelines simple.
What you actually get
The free tier mirrors the paid S2.1 Pro quality, so latency and voice fidelity remain unchanged. Because the endpoint is identical, existing monitoring and error‑handling logic continues to work. The only difference is the billing label – you’ll see zero cost on the usage dashboard.
Caveats to consider
- Rate‑limit uncertainty – “no hard usage cap” means there’s no explicit quota, but the service may still enforce fair‑use throttling under heavy load.
- Support level – free users typically receive community‑only assistance, so critical production issues might require a paid plan.
- Future pricing – today’s free access could be a limited‑time promotion; keep an eye on announcements to avoid surprise costs.
When to try it
Start a quick A/B test in a low‑traffic feature flag to compare the free model against your current TTS provider. If latency and quality meet your SLA, you can roll it out to broader user segments and eliminate the recurring TTS expense.
Sources: Fish Audio tweet