ElevenLabs Voice Cloning and Voice Design API vs Ultravox Voice Cloning

ElevenLabs Voice Cloning and Voice Design API

Instant clones from 1 to 2 minutes of audio on the $6 Starter plan. Instant clones rely on an attestation, not a check.

Ultravox Voice Cloning

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

ElevenLabs Voice Cloning and Voice Design API

1. Keep the source samples. A clone can't be downloaded and re-cloning sounds slightly different
2. Check requires_verification in the create response before using the voice ID
3. List your own clones with GET /v2/voices?category=cloned instead of paging the whole library
4. On system_busy retry with backoff. On too_many_concurrent_requests queue instead, the plan cap won't lift
5. PVC is asynchronous. Create, add samples, verify, train, then poll fine_tuning_state

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