Fish Audio S2 Pro
Fish Audio's previous-generation open S2 TTS with natural-language cues in brackets, multi-speaker dialogue and zero-shot voice cloning across 80+ languages.
S2 Pro is a cloud text-to-speech model from Fish Audio. It converts written text into natural, spoken audio, and can clone a voice from a short reference recording. It offers a choice of 8 voices. Voices can be tuned for speed, and output is available as MP3, WAV, and OPUS. It runs through Fish Audio and OpenRouter using your own API key, from $0.015 per 1,000 characters.
- Released
- May 2026
- Pricing
- $0.015 / 1k chars
- Type
- Text-to-speech
- Voices
- 8 to choose from
- Voice controls
- Speed
- Output formats
- MP3, WAV, OPUS
Samples
Generated with S2 Pro via OpenRouter: the same three scripts read by every text-to-speech model in the catalog, so the only thing that changes between two models’ clips is the model. Each model uses its own default voice; there is no shared voice to hold constant.
Baseline naturalness and pacing
The last train had already left, but she decided to walk anyway. The city was quieter than she remembered, and for the first time in weeks, she wasn't in a hurry.
Emotion, emphasis, and pauses
Wait — you're telling me it actually worked? After all that? I can't believe it. Honestly, I thought we'd lost the whole thing.
Decimals, percentages, version numbers
The API returned 3,481 results in 0.42 seconds, a 12 percent improvement over version 2.5. Latency at the 99th percentile dropped from 840 milliseconds to 610.
Fish Audio
Fish Audio builds expressive speech models with inline emotion cues, multi-speaker synthesis, and zero-shot voice cloning across 80+ languages.
fish.audio ↗Fish Audio's text-to-speech model for directed voice performances: you describe how each line should be delivered in square brackets, add sounds and pauses, and script several speakers in one call.
Fish Audio's recommended production TTS with natural-language cues in brackets, multi-speaker synthesis in one call, and zero-shot voice cloning across 83 languages.
Fish Audio's S2.1 Pro model at $0 for development and testing under fair-use limits, with the same bracket cues, multi-speaker synthesis and voice cloning but no latency or data-processing guarantees.
Fish Audio's speech-to-text model for multi-speaker conversations, which labels who is speaking and keeps emotion and vocal-event cues such as laughter in the transcript.