Fish Audio S2.1 Pro

Fish Audio S2.1 Pro is the latest text-to-speech model from Fish Audio, delivering high-quality synthesis across 83 languages with voice cloning and natural language control over emotion and prosody. It suits audiobooks, virtual assistants, video voiceovers, and other expressive use cases.

Its key advantage: on the Artificial Analysis Speech Arena, it holds an Elo of 1,153 (#13) and generates at 56.3 chars/sec with low latency and high throughput. Most notably, it is offered for free to all developers via API until July 24, 2026, with no hard cap and the same endpoint as paid plans. Existing users can simply switch to the model name “s2.1-pro-free” for instant zero-cost access.

Potential limitations: the free period may end, after which standard pricing could apply; free-tier usage might still be subject to soft limits or policy changes; emotion and cloning quality can vary by language and context, requiring real-world testing. The service relies entirely on Fish Audio’s cloud, so any platform changes could disrupt production.

Currently, deployment involves zero infrastructure cost, making it ideal for indie developers, multilingual content startups, and rapid prototyping.