Soniox Voice Cloning vs Ultravox Voice Cloning

Soniox Voice Cloning

One API call and a clip of up to 2 minutes. No consent capture or speaker verification, and the terms say so.

Ultravox Voice Cloning

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

Soniox Voice Cloning

1. Poll the voice until the target model's status is ready before using it in TTS
2. On voice_not_prepared call recompute, don't retry the TTS request
3. Don't retry voice_failed even though it's a 503. Create a new voice from a better clip
4. Use a key from the project that owns the voice, voices are per project
5. Keep the clip under 2 minutes and 35 MB, longer fails with voice_audio_too_long

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