Best for
Best for teams putting AI voice agents on real phone lines and testing them before they meet customers.
- Small and mid-sized
- Enterprise
AI Voice & Speech Comparison
Retell AI vs. Vapi
At a glance
At a glance
Best for
Best for developers putting voice agents on real phone lines for support, lead qualification or scheduling.
- Small and mid-sized
- Enterprise
Cataleo does not name a winner. Both statements come from the vendors themselves.
Full Comparison
| Criterion | Retell AI | Vapi |
|---|---|---|
| Starting price | From $0.07 / minute of calls Pay as you go, quoted by the vendor as $0.07 to $0.31 per minute for voice agents depending on the models, telephony and add-ons chosen, plus from $0.002 per message for chat agents. Enterprise is quoted by sales. | lower value From $0.05 / minute of calls Build plan, usage-based, plus $0.005 per SMS or chat message. Ten concurrent lines are included and further lines cost $10 / month each. Model provider costs for speech-to-text, the LLM and text-to-speech are passed through at cost, or nothing if you bring your own API keys. |
| Free trial | $10 in free credits, no contract and no commitment; 20 concurrent calls are included | Not stated |
| Commercial use | Yes, usage-based | Yes, usage-based |
| Output | Voice agents for inbound and outbound phone calls and web calls, plus chat agents over SMS and a web widget | Voice agents for inbound and outbound phone calls, web voice, and SMS or chat |
| API | Yes, REST API with Node.js and Python libraries, webhooks and an MCP server | Yes, REST API, CLI and SDKs |
| Hosting | Cloud on AWS; the vendor states it does not currently operate services within the European Union | Not stated |
| Voice cloning | Yes, custom voices can be added by searching ElevenLabs community voices, importing an existing clone or training one from uploaded recordings, with Inworld, Cartesia, MiniMax, ElevenLabs and Retell's own platform clones as providers; up to 100 custom voices per account | Not part of Vapi itself; voices come from connected providers such as ElevenLabs and Deepgram |
| Real-time use | Yes, live inbound and outbound phone calls and browser web calls, with a proprietary turn-taking model, batch calling for campaigns and live monitoring that lets a human listen in or step in | Yes, live inbound and outbound phone and web conversations at an average latency under 500 ms |
| Languages | 57 languages are listed for text-to-speech and 55 for speech recognition, and a language needs a provider on both sides to be usable. An agent runs either in a single language or as a multilingual agent across a chosen set | Depends on the providers chosen for a given assistant: automatic language detection and code-switching with Deepgram (100+ languages), Google STT (125+) or Gladia (110+), while Azure, OpenAI Whisper, Speechmatics and Talkscriber run one language at a time; on the voice side Vapi's own voices cover 40+ languages, Azure 140+ and ElevenLabs 30+. The languages an assistant may use have to be listed in its system prompt |
| Speech-to-speech and dubbing | A call runs as spoken conversation by chaining speech recognition, a language model and text-to-speech; dubbing of existing recordings is not part of the product | Yes, a call runs as spoken conversation by chaining speech-to-text, a language model and text-to-speech, with natural turn-taking |
| Editing and controls | Single and multi-prompt agents or node-based conversation flows, knowledge bases, expressive mode for emotion and emphasis, custom pronunciation with IPA, CMU, Pinyin or Jyutping, denoising and interruption sensitivity, voicemail and IVR handling, plus a playground, simulation tests, A/B testing and post-call analysis | Assistants for a single prompt with tools, Squads for multi-assistant orchestration, tool calls into APIs and databases mid-conversation, plus testing and call observability |
| Consent and trust | HIPAA compliant, SOC 2 Type 1 and Type 2 certified and GDPR compliant, with a BAA and a DPA including EU standard contractual clauses available for self-signing at no extra fee. Per-agent data retention runs from 1 day to 2 years, PII can be excluded from what is stored, and recording URLs can be signed. Services are not currently operated inside the EU | SOC 2, HIPAA and PCI compliance with SSO, OAuth and role-based access control; HIPAA is a $2,000 / month add-on and zero data retention $1,000 / month on both plans |
| MCP-ready | Yes | Yes |
| Deployment | Cloud (SaaS), Browser-based | Cloud (SaaS), Browser-based |
| Support | Not stated | Email helpdesk, Community forum |
| Onboarding | Documentation and knowledge base | Documentation and knowledge base |
| Company size | Small and mid-sized, Enterprise | Small and mid-sized, Enterprise |
| Integrations | Twilio, Telnyx, Vonage, Genesys Cloud, Five9, Avaya, Amazon Connect, HubSpot, Make, n8n, GoHighLevel | OpenAI, Anthropic, Groq, Deepgram, Gladia, ElevenLabs, Salesforce, HubSpot, Zapier, Slack, Google Workspace |
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The short version
Key Differences
- Starting price Retell AI From $0.07 / minute of calls Vapi From $0.05 / minute of calls
- Output Retell AI Voice agents for inbound and outbound phone calls and web calls, plus chat agents over SMS and a web widget Vapi Voice agents for inbound and outbound phone calls, web voice, and SMS or chat
- API Retell AI Yes, REST API with Node.js and Python libraries, webhooks and an MCP server Vapi Yes, REST API, CLI and SDKs
- Voice cloning Retell AI Yes, custom voices can be added by searching ElevenLabs community voices, importing an existing clone or training one from uploaded recordings, with Inworld, Cartesia, MiniMax, ElevenLabs and Retell's own platform clones as providers; up to 100 custom voices per account Vapi Not part of Vapi itself; voices come from connected providers such as ElevenLabs and Deepgram
- Real-time use Retell AI Yes, live inbound and outbound phone calls and browser web calls, with a proprietary turn-taking model, batch calling for campaigns and live monitoring that lets a human listen in or step in Vapi Yes, live inbound and outbound phone and web conversations at an average latency under 500 ms
Every line is one datapoint from the table above, picked automatically. Nothing here is written text.
The trade-offs
Strengths and Limitations
Retell AI
Strengths
- Usage-based per-minute pricing with no contract and $10 in free credits to start
- Testing tooling built into the product: playground, simulation runs, batch tests and A/B splits of live traffic
- Custom voices can be cloned or imported across several voice providers
- HIPAA, SOC 2 Type 1 and Type 2 and GDPR, with BAA and DPA available for self-signing at no extra fee
Limitations
- The per-minute rate varies widely with the models, telephony and add-ons chosen, so the entry rate is not the rate to budget with
- The vendor states it does not currently operate services within the European Union
- Retell-managed phone numbers cover the US and Canada only; elsewhere a number has to be brought in
- Building and running an agent assumes developer work; there is no packaged seat-based plan
Vapi
Strengths
- Per-minute pricing with model provider costs passed through at cost
- Bring your own provider keys and the pass-through drops to nothing
- Free choice of speech-to-text, model and voice provider across dozens of options
- Official MCP server lets external AI agents drive Vapi's APIs
Limitations
- HIPAA compliance and zero data retention are monthly add-ons rather than included
- Total cost depends on which model, transcription and voice providers you choose
- Concurrent lines beyond the first ten cost $10 per month each
- A platform to build on, not a finished call-centre product
Plans
Pricing
Retell AI
- Pay as you go $0.07 Per minute and up, quoted by the vendor as $0.07 to $0.31 per minute for voice agents and from $0.002 per message for chat agents. Includes $10 in free credits and 20 concurrent calls, with no contract.
- Enterprise Not stated Contact sales. Custom pricing for higher volumes, with dedicated support and implementation, custom compliance terms covering HIPAA, SSO and a DPA, no cap on concurrent calls and a dedicated server option.
Vapi
- Build $0.05 Per minute of calls, usage-based, plus $0.005 per SMS or chat message. Ten call concurrency included, additional lines $10 / month each. Model provider costs at cost. Community Discord and email support.
- Scale Not stated Annual contract with a fixed platform fee and committed volume, volume-based per-minute pricing on quote, enterprise features including SOC 2, HIPAA and PCI, a dedicated account team and a custom support SLA.
What users say
Review Scores · opens after launch
Retell AI
- Ease of use
- Not rated yet
- User interface
- Not rated yet
- Onboarding
- Not rated yet
- Support and service
- Not rated yet
- Value for money
- Not rated yet
- Features
- Not rated yet
No reviews yet. Be the first to review this tool. Every review is checked for fairness before it appears, and the vendor cannot have one removed.
Vapi
- Ease of use
- Not rated yet
- User interface
- Not rated yet
- Onboarding
- Not rated yet
- Support and service
- Not rated yet
- Value for money
- Not rated yet
- Features
- Not rated yet
No reviews yet. Be the first to review this tool. Every review is checked for fairness before it appears, and the vendor cannot have one removed.
Where this comes from
Where this comes from
Retell AI https://www.retellai.com · checked against the official source on 2026-09-13
Vapi https://vapi.ai · checked against the official source on 2026-08-30
This table lists factual criteria taken from information the vendors publish themselves. For how we put it together, see the methodology.