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Fish Audio

S2.1 Pro

S2.1 Pro is Fish Audio's recommended production text-to-speech model, covering 83 languages with natural language prosody control and two-speaker dialogue in a single request. Your use is subject to Fish Audio's Terms & Privacy Policies.

Free
Use with AI GatewayView docs
import { experimental_generateSpeech as generateSpeech } from 'ai';
import { gateway } from '@ai-sdk/gateway';
import { writeFile } from 'node:fs/promises';


const result = await generateSpeech({
  model: gateway.speechModel('fish-audio/s2.1-pro'),
  text: 'Hello from the Vercel AI Gateway!',
  // Browse voices at https://fish.audio/app/discovery
  // Open a voice, then use "Copy Model Id" in its "..." menu.
  voice: '933563129e564b19a115bedd57b7406a',
});


await writeFile('speech.mp3', result.audio.uint8Array);
Read docs
OverviewAboutProvidersSimilarFAQ

Copy link to headingFrequently Asked Questions

  • What is S2.1 Pro built for?

    Production text-to-speech. Fish Audio recommends it as its production model, with better quality, latency, and throughput than S2 Pro.

  • How many languages does S2.1 Pro support?

    83.

  • How do I control emotion and delivery?

    Write direction inline in square brackets, such as [whispers sweetly]. The model interprets the description rather than matching a fixed tag list, so phrasing outside the documented set still works.

  • Can S2.1 Pro render a conversation?

    Yes. Write both sides in one text input, tag each turn with a speaker index, and the model returns a single audio file with both voices. Two speakers per request.

  • How does S2.1 Pro compare to S2 Pro?

    It is the improved version, preferred in roughly three of every five head-to-head listening judgements, with better latency and throughput and three more supported languages.

  • Is there a free way to try S2.1 Pro?

    Yes. Fish Audio publishes a free development tier with the same model quality and language coverage, without latency or availability guarantees. Use it for evaluation and prototyping.

  • Does S2.1 Pro support Zero Data Retention?

    Zero Data Retention is not currently available for this model. Zero Data Retention is offered on a per-provider basis. See https://vercel.com/docs/ai-gateway/capabilities/zdr for details.