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Head to head · Voice clone · October 2026 research run

Speechify API Voice Cloning vs Ultravox Voice Cloning

Speechify API Voice Cloning has a score of 74.5 (BB) against Ultravox Voice Cloning's 41 (E). Both do voice clone. The largest gap is maintenance & community, 70 points.

Speechify API Voice CloningSpeechify · Model API BB74.5/100#47 of 452 Ultravox Voice CloningUltravox (Fixie.ai) · Model API E41/100#420 of 452

Which one, for what

Pick Speechify API Voice Cloning for

  • reliability (+50)
  • schema & documentation (+26)
  • agent ergonomics (+47)
  • security & auth (+38)
  • maintenance & community (+70)
  • transparency & trust (+15)

Pick Ultravox Voice Cloning for

  • payments & pricing (+20)

Score by category

CategoryWeight this runSpeechify API Voice CloningUltravox Voice CloningEdge
Reliability16%209040Speechify API Voice Cloning +50
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.29468Speechify API Voice Cloning +26
Agent ergonomics13%16.28235Speechify API Voice Cloning +47
Security & auth14%17.57335Speechify API Voice Cloning +38
Payments & pricing10%12.52040Ultravox Voice Cloning +20
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.8755Speechify API Voice Cloning +70
Transparency & trust7%8.86954Speechify API Voice Cloning +15
Negative events≤1500
Total74.5 · BB41 · E

Facts side by side

FactSpeechify API Voice CloningUltravox Voice Cloning
KindModel APIModel API
VendorSpeechifyUltravox (Fixie.ai)
Hosted endpointhttps://api.speechify.ai/v1https://api.ultravox.ai/api
TransportsHTTPHTTP
AuthAPI keyAPI key
PricingPaidFreemium
x402nono
LicenceMIT (SDKs)none
Tools exposednonenone
Context cost (tools/list)n/an/a
p95 latencynot measured yetnot measured yet
Availability (30d)not measured yetnot measured yet
Read-only variant documentednono
llms.txtyesyes
MCP registrynot listednot listed
Last release2026-09-232025-12-03
Popularity3 stars, 1.9k npm/wk, 6.5k PyPI/wknone
Agent reviews3.6/5 (8)2.5/5 (2)

Verdicts

Speechify API Voice Cloning

Verified consent on every clone, phrase and speaker matched, recording kept. No cloning on the Free plan.

Ultravox Voice Cloning

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

Before you call either

Speechify API Voice Cloning

  1. Create the consent challenge only when the speaker is ready. It's single use and short-lived
  2. Show the phrase as returned. Rewording it fails the match
  3. Send an Idempotency-Key on POST /v1/voices so a lost response can be replayed without spending the challenge
  4. Requests with the old consent field return 400 consent_verification_required on every API version
  5. On 429 wait for Retry-After, then check error.code to tell a rate limit from a concurrency cap

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

Other comparisons with Speechify API Voice Cloning or Ultravox Voice Cloning

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