Core text speech 2.5 Features

The model is optimized for high-speed performance, delivering a Time To First Byte (TTFB) of approximately 180ms. This makes the text speech 2.5 model significantly faster than OpenAI TTS-1-HD, providing a seamless experience for real-time voice assistants and interactive applications that require immediate verbal feedback.

To achieve high-fidelity zero-shot voice cloning, you only need a 5 to 10-second audio reference. The text speech 2.5 system uses this sample to extract vocal characteristics, allowing the cloned voice to read any text input with high similarity (94.1%) across 30+ supported languages while maintaining the original speaker's identity.

Yes, it supports studio-grade 48kHz output in various formats including MP3, WAV, PCM, and Opus. This resolution is superior to the 24kHz industry standard, ensuring that synthesized speech sounds professional and clear, which is essential for podcasts, audiobooks, and high-end digital human animations.

Each individual request can process text up to 4,096 characters. For longer documents or extensive scripts, we recommend chunking the text into smaller segments. This prevents processing timeouts and ensures the neural engine maintains consistent prosody and emotional inflection throughout the entire audio generation process.

Privacy is a core priority. Any text or audio samples sent through our API to the text speech 2.5 preview model are excluded from ByteDance's training datasets by default. Your proprietary scripts and voice cloning data remain secure and are used solely for generating your specific request outputs.

Standard voice synthesis is priced at $15.00 per 1 million characters. For high-definition or cloned voices, the rate is $30.00 per 1 million characters. GPTProto.com provides unified billing, allowing you to access these advanced features without managing multiple separate enterprise contracts with individual vendors.