Fish Audio Voice Cloning API vs Ultravox Voice Cloning

Fish Audio Voice Cloning API

Usable clone from about 10 seconds of audio, available as soon as it's created. No consent or speaker verification in the API.

Ultravox Voice Cloning

One multipart request with a 30 to 60 second sample. No consent or speaker verification, only a warranty in the terms.

Fish Audio Voice Cloning API

1. Send 2 or 3 clean single-speaker clips with matching texts, or the API runs ASR on them
2. Pass the model _id as reference_id in TTS. Check state before relying on it
3. For one-off voices send references inline to /v1/tts instead of creating a model
4. Send the model: voice-design-1 header on voice design calls
5. Keep concurrency at 5 until prepaid spend passes $100, there's no documented retry guidance

Ultravox Voice Cloning

1. Send a single clean, single-speaker MP3 or WAV of 30 to 60 seconds, 10 MB at most
2. Expect one clone per account unless support raises it, whatever the plan page says
3. Test the voice in the Playground before putting it on a live agent
4. Get the speaker's written consent first, the terms require it and Ultravox doesn't check