Overview

Fish Audio S2.1 Pro is a flagship text-to-speech model built for expressive multilingual speech generation with realtime responsiveness.

It is designed for applications that need more than neutral narration: dynamic emotional delivery, natural-language voice direction, streaming output, multilingual switching, and multi-speaker dialogue generation from a single model.

Strengths

Natural-Language Voice Control

S2.1 Pro uses bracket-based natural-language cues for delivery shaping rather than restricting expression to a small fixed control vocabulary. This makes it easier to direct emotion, pacing, emphasis, breaths, pauses, and paralinguistic behavior directly in the text.

Realtime Speech Generation

The model is optimized for low-latency streaming with very fast time to first audio, making it a strong fit for interactive voice applications rather than only offline rendering workflows.

Multilingual Range

S2.1 Pro supports more than 80 languages with automatic language detection. It is useful for global voice products that need one model to handle multilingual output without heavy per-language workflow branching.

Multi-Speaker Dialogue

The model supports multi-speaker dialogue generation, which makes it especially useful for conversational scenes, character exchanges, dramatized content, and interactive storytelling workflows.

Expressive Conversational Output

S2.1 Pro is built for emotionally varied speech with richer delivery shaping than basic TTS systems. It works well for characters, agents, audiobooks, dialogue-heavy content, and spoken experiences that need tone shifts inside a single generation.

Open Serving and Deployment Flexibility

The model is positioned as an open, next-generation TTS system with a modern serving stack, which makes it relevant for teams that care about deployment flexibility alongside output quality.

Capabilities

Text-to-Audio

S2.1 Pro converts text into expressive speech with strong control over delivery, language, and speaking style.

Streaming Output

The model is designed for realtime generation workflows where audio begins quickly and can be streamed into live applications.

Dialogue and Character Speech

S2.1 Pro is well suited to applications that need conversations, character performances, or multi-voice narrative structure instead of single-speaker flat narration.

Input and Output

• AIR ID: fishaudio:s2.1@pro
• Input: text with optional bracket-based delivery cues and dialogue structure
• Output: synthesized speech audio
• Language coverage: 80+ languages with automatic language detection
• Streaming: supported

Best Fit

• Conversational voice agents
• Character and game dialogue
• Audiobooks and spoken storytelling
• Multilingual text-to-speech products
• Realtime voice interfaces