[Fish Audio](/ai-gateway/models/labs/fish-audio) # S1 S1 is Fish Audio's earlier text-to-speech model, covering 13 languages with an explicit emotional vocabulary of more than 60 expressions, tone markers, and audio effects. Your use is subject to Fish Audio's [Terms](https://fish.audio/terms/) & [Privacy](https://fish.audio/privacy/) Policies. Free [Use with AI Gateway](https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Futm_source%3Dgateway-model-page%26utm_campaign%3Dai-gateway-models&title=Get+Started+with+Vercel+AI+Gateway) [View docs](https://vercel.com/docs/ai-gateway) ``` 1import { experimental_generateSpeech as generateSpeech } from 'ai'; 2import { gateway } from '@ai-sdk/gateway'; 3import { writeFile } from 'node:fs/promises'; 4 5const result = await generateSpeech({ 6 model: gateway.speechModel('fish-audio/s1'), 7 text: 'Hello from the Vercel AI Gateway!', 8 // Browse voices at https://fish.audio/app/discovery 9 // Open a voice, then use "Copy Model Id" in its "..." menu. 10 voice: '933563129e564b19a115bedd57b7406a', 11}); 12 13await writeFile('speech.mp3', result.audio.uint8Array); ``` [Read docs](https://vercel.com/docs/ai-gateway/sdks-and-apis/ai-sdk) [Overview](/ai-gateway/models/s1) [About](/ai-gateway/models/s1/about) [Providers](/ai-gateway/models/s1/providers) [Similar](/ai-gateway/models/s1/similar) [FAQ](/ai-gateway/models/s1/faq) ## [Copy link to heading](#playground)Playground Try out S1 by Fish Audio. Usage is billed to your team at API rates. Free users (those who haven't made a payment) get $5 of credits every 30 days. ![fish-audio logo](/vc-ap-vercel-marketing/_next/image?url=https%3A%2F%2F7nyt0uhk7sse4zvn.public.blob.vercel-storage.com%2Fdocs-assets%2Fstatic%2Fdocs%2Fai-gateway%2Flogos%2Ffish-audio.png%3Fv%3D1785975667162&w=48&q=75)S1 Text The text the model will read aloud. Voice SarahPoloSeleneAdrianEthan ![fish-audio logo](/vc-ap-vercel-marketing/_next/image?url=https%3A%2F%2F7nyt0uhk7sse4zvn.public.blob.vercel-storage.com%2Fdocs-assets%2Fstatic%2Fdocs%2Fai-gateway%2Flogos%2Ffish-audio.png%3Fv%3D1785975667162&w=96&q=75) Your generated audio will appear here ## [Copy link to heading](#providers)Providers Route requests across multiple providers. Copy a provider slug to set your preference. Visit the [docs](/docs/ai-gateway/provider-options) for more info. Using a provider means you agree to their terms, listed under Legal. | Provider | | --- | | Input | Capabilities | ZDR | No Training | Release Date | | | --- | --- | --- | --- | --- | --- | | ![fish-audio logo](/vc-ap-vercel-marketing/_next/image?url=https%3A%2F%2F7nyt0uhk7sse4zvn.public.blob.vercel-storage.com%2Fdocs-assets%2Fstatic%2Fdocs%2Fai-gateway%2Flogos%2Ffish-audio.png%3Fv%3D1785975667162&w=48&q=75) [Fish Audio](/ai-gateway/models/providers/fish-audio) Free Legal:[Terms](https://fish.audio/terms/)•[Privacy](https://fish.audio/privacy/) | Free | | | | 10/20/2025 | | | --- | --- | --- | --- | --- | --- | --- | ## [Copy link to heading](#more-models-by-fish-audio)More models by Fish Audio All Speech Transcription | Model | | --- | | Context | Latency | Throughput | Input | Output | Cache | Web Search | Capabilities | Providers | ZDR | No Training | Release Date | | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | ![fish-audio logo](/vc-ap-vercel-marketing/_next/image?url=https%3A%2F%2F7nyt0uhk7sse4zvn.public.blob.vercel-storage.com%2Fdocs-assets%2Fstatic%2Fdocs%2Fai-gateway%2Flogos%2Ffish-audio.png%3Fv%3D1785975667162&w=48&q=75) [fish-audio/s2.1-pro](/ai-gateway/models/s2.1-pro) | | | | Free | Free | | — | | ![fish-audio logo](/vc-ap-vercel-marketing/_next/image?url=https%3A%2F%2F7nyt0uhk7sse4zvn.public.blob.vercel-storage.com%2Fdocs-assets%2Fstatic%2Fdocs%2Fai-gateway%2Flogos%2Ffish-audio.png%3Fv%3D1785975667162&w=48&q=75) | | | 07/28/2026 | | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | ![fish-audio logo](/vc-ap-vercel-marketing/_next/image?url=https%3A%2F%2F7nyt0uhk7sse4zvn.public.blob.vercel-storage.com%2Fdocs-assets%2Fstatic%2Fdocs%2Fai-gateway%2Flogos%2Ffish-audio.png%3Fv%3D1785975667162&w=48&q=75) [fish-audio/s2-pro](/ai-gateway/models/s2-pro) | | | | Free | Free | | — | | ![fish-audio logo](/vc-ap-vercel-marketing/_next/image?url=https%3A%2F%2F7nyt0uhk7sse4zvn.public.blob.vercel-storage.com%2Fdocs-assets%2Fstatic%2Fdocs%2Fai-gateway%2Flogos%2Ffish-audio.png%3Fv%3D1785975667162&w=48&q=75) | | | 03/09/2026 | | | ![fish-audio logo](/vc-ap-vercel-marketing/_next/image?url=https%3A%2F%2F7nyt0uhk7sse4zvn.public.blob.vercel-storage.com%2Fdocs-assets%2Fstatic%2Fdocs%2Fai-gateway%2Flogos%2Ffish-audio.png%3Fv%3D1785975667162&w=48&q=75) [fish-audio/transcribe-1](/ai-gateway/models/transcribe-1) | | | | Free | Free | | — | | ![fish-audio logo](/vc-ap-vercel-marketing/_next/image?url=https%3A%2F%2F7nyt0uhk7sse4zvn.public.blob.vercel-storage.com%2Fdocs-assets%2Fstatic%2Fdocs%2Fai-gateway%2Flogos%2Ffish-audio.png%3Fv%3D1785975667162&w=48&q=75) | | | 03/01/2026 | | ## [Copy link to heading](#about-s1)About S1 S1 is Fish Audio's earlier text-to-speech model, a 4-billion-parameter model covering 13 languages including English, Chinese, Japanese, German, French, Spanish, Korean, Arabic, Russian, Dutch, Italian, Polish, and Portuguese. Fish Audio keeps it available for existing integrations. The difference from the S2 generation is how you direct it. S1 uses an explicit vocabulary written in parentheses: more than 60 expressions spanning basic and advanced emotions, tone markers, and audio effects. Where the S2 models interpret free-form description, S1 matches against a defined set. That is more limiting and more predictable, which is the tradeoff to weigh. On transcription-accuracy measures of its output, S1 posts a word error rate of 0.8 percent and a character error rate of 0.4 percent, and it ranked first on TTS-Arena2 at the time of its release. Integration uses the AI SDK's speech generation function. ## [Copy link to heading](#what-to-consider-when-choosing-a-provider)What To Consider When Choosing a Provider - Configuration: S1 is a previous generation. Fish Audio recommends S2.1 Pro for production, and language coverage is the clearest gap: 13 languages here against 83. For a new integration, start with S2.1 Pro unless the fixed emotional vocabulary is specifically what you want. - Configuration: That vocabulary is the one reason to prefer S1. A defined set of expressions and tone markers produces more repeatable results than interpreted free-form direction, which matters when a script has to sound the same across regenerations. - Configuration: Since it is maintained for existing integrations rather than actively developed, weigh how long you expect to depend on it before building something new on top. - Zero Data Retention: Zero Data Retention is offered on a per-provider and model basis. See the [documentation](https://vercel.com/docs/ai-gateway/security-and-compliance/zdr) for details. - Authentication: AI Gateway authenticates requests using an [API key](https://vercel.com/docs/ai-gateway/authentication-and-byok#api-key-authentication) or [OIDC token](https://vercel.com/docs/ai-gateway/authentication-and-byok#oidc-token-authentication). You do not need to manage provider credentials directly. ## [Copy link to heading](#when-to-use-s1)When to Use S1 ### Best for - Existing S1 Integrations: Already built against its parenthesis syntax - Repeatable Delivery: A fixed vocabulary instead of interpreted direction - Explicit Audio Effects: Tone markers chosen from a defined set - The 13 Supported Languages: Where wider coverage is unnecessary ### Consider alternatives when - New Integrations: S2.1 Pro is the recommended production model - Wider Language Coverage: S2.1 Pro supports 83 languages against 13 - Free-Form Direction: The S2 generation interprets plain language - Long-Term Support: This model is maintained rather than actively developed ## [Copy link to heading](#conclusion)Conclusion S1 is Fish Audio's earlier voice model, kept for existing integrations and distinguished by an explicit emotional vocabulary. Point `fish-audio/s1` at AI Gateway if you depend on that predictability, and choose S2.1 Pro for anything new.