Retell AI

Best for: Regulated or enterprise workloads - compliance attestations and an enterprise plan; AI agents and automation - an agent-ready surface (MCP / llms.txt); Teams needing broad API coverage out of the box

Avoid if: You want to try it free before paying

Pricing model

Usage-based [2]retellai.com/pricing“Voice Infrastructure: $0.055/min”retellai.com/pricing“$0.07-$0.31 / min for AI Voice Agents”

Published pricing

✓ Yes [3]retellai.com/pricing“Voice Agent Rate: $0.07-$0.31 / min for AI Voice Agents. Voice Infrastructure: $0.055/minute. Text-to-Speech Options: $0.015-$0.040/minute. LLM Costs: Range from $0.003/minute to $0.16/minute. Telephony: $0.015/min for US.”

Free tier

✗ No [4]retellai.com/pricing“$10 in free credits with full platform access, no commitments”retellai.com/pricing“The $10 appears to be a one-time trial allowance for new users. There is no mention of recurring monthly free minutes.”

Free tier details

$10 one-time trial credit on sign-up (not a recurring free tier)

Self-serve signup

✓ Yes

Requires sales call

✗ No

Enterprise plan

✓ Yes [5]retellai.com/pricing“Enterprise Plan: Custom Pricing for both voice and chat agents. Concurrent Calls: No cap; custom options starting 50+ calls. Additional Features: Dedicated implementation support, custom MSA/DPA terms, role-based access control, dedicated stable server, custom SSO, 24/7 Omnichannel Support with Dedicated Portal.”

• Built-in telephony
• Outbound calling
• BYO models

Supported actions

realtime_conversation, inbound_telephony, outbound_telephony, sip_trunking, web_calling_webrtc, call_transfer, function_calling, tool_calling, interruption_handling, byo_llm, byo_voice, knowledge_base, batch_calling, call_recording, call_analytics, post_call_analysis, ai_quality_assurance, pii_redaction, dtmf_capture, ivr_navigation, dynamic_variable_injection, webhooks, mcp_server, simulation_testing, voice_cloning, safety_guardrails, voicemail_detection, ab_testing, agent_versioning [6]docs.retellai.com/llms.txt“Inbound and outbound calling on Retell-managed or imported numbers. SIP integration via elastic SIP trunking with providers (Twilio, Telnyx, Vonage, Genesys, Five9, Avaya). Web calling through WebRTC with the Retell Web SDK. Call transfer (warm/cold) to humans or other AI agents. Batch calling for campaign outreach. Function calling (tool use) for API integration mid-call. Interruption handling with configurable sensitivity. Bring-your-own-LLM via WebSocket integration. Custom voice support (cloning, community voices, platform voices). Call recording with secure URL expiration.”docs.retellai.com/deploy/concurrency“Calls that exceed your normal limit (but stay within the burst limit) will proceed with an $0.10/min surcharge applied to the entire call duration.”

Regions

United States, Canada, International (via custom SIP/BYO telephony) [7]retellai.com/blog/enterprise-voice-ai-compliance-guide“Call processing occurs in US regions (AWS US-East/US-West)”docs.retellai.com/general/compliance“we do not currently operate services within the European Union”

Languages

English (US), English (India), English (UK), English (Australia), English (New Zealand), Spanish (Spain), Spanish (Latin America), French, Chinese (Mandarin), German, Hindi, Japanese, Portuguese (Portugal), Portuguese (Brazil), Russian, Italian, Korean, Dutch, Dutch (Belgium), Polish, Turkish, Vietnamese, Romanian, Danish, Finnish, Greek, Indonesian, Norwegian, Slovak, Swedish, Bulgarian, Hungarian, Malay, Catalan, Thai, 50+ languages total (dashboard is source of truth; list expands continuously) [8]community.retellai.com/t/22-new-languages-thats-50-live-for-all-retell-customers/163“We just shipped 22 new languages, that's 50+ Live for all Retell customers”retellai.com/blog/how-to-use-ai-phone-agents-for-multilingual-communication“Retell AI currently supports 31+ languages, including: English (US, India, UK, Australia, New Zealand), Spanish (Spain, Latin America), French, Chinese, German, Hindi, Japanese, Portuguese (Portugal, Brazil), Russian, Italian, Korean, Dutch, Dutch (Belgium), Polish, Turkish, Vietnamese, Romanian, Danish, Finnish, Greek, Indonesian, Norwegian, Slovak, Swedish, Bulgarian, Hungarian, Malay, Catalan, and Thai.”

Input types

PSTN phone call, SIP, WebRTC, web widget, audio stream [9]docs.retellai.com/llms.txt“Inbound and outbound calling on Retell-managed or imported numbers. SIP integration via elastic SIP trunking with providers. Web calling through WebRTC with the Retell Web SDK.”

Output types

audio stream, call transcript, webhook events, call recording, structured call summary, post-call analysis, SMS [10]docs.retellai.com/llms.txt“Call recording with secure URL expiration. Post-call analysis with custom field extraction. Webhook-based event delivery. Three event types: call_started, call_ended, call_analyzed.”

Webhooks

✓ Yes [11]docs.retellai.com/features/webhook“call_started, call_ended, call_analyzed, transcript_updated, transfer_started, transfer_bridged, transfer_cancelled, transfer_ended, chat_started, chat_ended, chat_analyzed”

Sandbox / test mode

✗ No

SDK languages

Python, Node.js, JavaScript (browser/client) [12]docs.retellai.com/llms.txt“Retell provides official SDKs for Node.js and Python, offering typed clients, simplified API key auth, structured error handling, and full coverage of voice and chat endpoints.”

MCP server

✓ Yes [13]docs.retellai.com/get-started/mcp-server“Retell supports the Model Context Protocol (MCP) so you can build Retell AI voice agents directly from MCP-capable clients.”

SOC 2

SOC 2 Type II [14]retellai.com“HIPAA, SOC2 Type II, and GDPR compliance”docs.retellai.com/general/compliance“SOC 2 Type 1 & Type 2 certified”

HIPAA

✓ Yes [15]retellai.com/blog/hipaa-compliant-voice-ai-without-enterprise-contract“HIPAA compliance is not gated to enterprise. Every Retell account, including pay-as-you-go, can operate as a HIPAA-eligible workload once a BAA is in place.”docs.retellai.com/general/compliance“HIPAA compliant. Our BAA and DPA agreements are available for self signing.”

GDPR

✓ Yes [16]docs.retellai.com/general/compliance“we do not currently operate services within the European Union”docs.retellai.com/general/compliance“GDPR compliant. Retell leverages AWS infrastructure, which includes a GDPR-compliant Data Processing Addendum.”

ISO 27001

✗ No [17]docs.retellai.com/general/compliance“HIPAA compliant, GDPR compliant, SOC 2 Type 1 & Type 2 certified”

PCI DSS

✗ No [18]docs.retellai.com/general/compliance“HIPAA compliant, GDPR compliant, SOC 2 Type 1 & Type 2 certified”

Published SLA

✓ Yes [19]docs.retellai.com/reliability/reliability-overview“Retell guarantees >99.9% uptime”retellai.com/legal/terms-of-service“Retell AI shall use commercially reasonable efforts to maintain at least 99.5% uptime for the Services, excluding scheduled maintenance windows (not to exceed six (6) hours per month) and events of force majeure”

Rate limits

Pay-as-you-go plan includes 20 free concurrent calls; additional concurrent call capacity at $8/concurrent call/month. Burst mode allows temporarily exceeding the limit at a $0.10/min surcharge for the entire call duration (burst cap = lower of 3× limit or limit + 300). Max call duration is 1 hour (expandable to 2 hours). Enterprise plan: no cap, custom options starting at 50+ concurrent calls. [20]docs.retellai.com/deploy/concurrency“Calls that exceed your normal limit (but stay within the burst limit) will proceed with an $0.10/min surcharge applied to the entire call duration. Burst capacity is calculated as the lower of 3× your limit or your limit + 300.”docs.retellai.com/deploy/concurrency“Pay-As-You-Go workspaces are allocated a quota of 20 concurrent calls by default”

Known restrictions

Services not currently operational within the EU (GDPR compliant via AWS but US-region only), Not designed for medical, emergency, aviation, nuclear, or safety-critical environments, Cannot submit HIPAA/PCI/biometric data without a signed BAA or express authorization, Reselling AI-generated voices as standalone products is prohibited, TCPA, FCC, and Do-Not-Call compliance is the customer's responsibility [21]retellai.com/legal/terms-of-service“Services not designed for medical, emergency, aviation, nuclear, or safety-critical environments. Cannot submit heightened-security data (HIPAA, PCI DSS, biometric data) unless expressly authorized or covered by a BAA.”docs.retellai.com/general/compliance“we do not currently operate services within the European Union”

• Docs
• llms.txt
• Changelog
• Status page

Docs rendering: static · llms.txt present

API style

rest

Base URL

https://api.retellai.com

Version

v2

Versioning

url

Stability

ga

Auth methods

api_key

Idempotency keys

✗ No

Error format

vendor-specific JSON: {"status": "error", "message": "..."}

Webhook signing

hmac_sha256

Rate limit

20 / concurrent calls

SDKs

• Python retell-sdk · repo
• Node.js retell-sdk · repo
• JavaScript (browser/client) retell-client-js-sdk · repo

• Auth docs
• Quickstart
• MCP server
• Webhook events
• Deprecation policy

Launched

2023-01-01

GA

2024-02-01

Notable customers

Lenovo, Asbury Auto, Anker, StorageVault

• ElevenLabs Conversational AI (ElevenAgents)

  "Deploy human-like Conversational AI in minutes. ElevenLabs delivers low latency interactions in dozens of languages with enterprise-grade security."

  Hybrid · free tier · public pricing · self-serve

• OpenAI Realtime API (gpt-realtime)

  "The Realtime API enables low-latency, bidirectional audio communication for building voice agents and audio applications."

  Usage · public pricing · self-serve

• Telnyx Voice AI Agents

  "Carrier-grade Voice AI from Telnyx. Sub-200ms latency, 80+ languages, A-level STIR/SHAKEN attestation, and one platform that replaces 5 vendors."

  Usage · public pricing · self-serve

• Twilio ConversationRelay

  "Twilio's Conversation Relay empowers you to build powerful AI voice experiences for your customers. Let Twilio handle the heavy lifting of speech recognition, text-to-speech, and voice synthesis."

  Usage · public pricing · self-serve

• Vapi

  "Build and deploy voice agents that deliver the outcomes you want at the scale your customers need."

  Usage · free tier · public pricing · self-serve

• Cartesia Line

  "Turn any text agent into a world-class conversational agent, deployed anywhere."

  Hybrid · free tier · public pricing · self-serve

Retell AI alternatives · Retell AI vs ElevenLabs Conversational AI (ElevenAgents) · All Realtime Voice Agent APIs APIs

Each field above carries a numbered source - hover for a preview, click to jump here.

1. ↑Description: retellai.com
2. ↑Pricing model: retellai.com · retellai.com
3. ↑Published pricing: retellai.com
4. ↑Free tier: retellai.com · retellai.com
5. ↑Enterprise plan: retellai.com
6. ↑Supported actions: docs.retellai.com · docs.retellai.com
7. ↑Regions: retellai.com · docs.retellai.com
8. ↑Languages: community.retellai.com · retellai.com
9. ↑Input types: docs.retellai.com
10. ↑Output types: docs.retellai.com
11. ↑Webhooks: docs.retellai.com
12. ↑SDK languages: docs.retellai.com
13. ↑MCP server: docs.retellai.com
14. ↑SOC 2: retellai.com · docs.retellai.com
15. ↑HIPAA: retellai.com · docs.retellai.com
16. ↑GDPR: docs.retellai.com · docs.retellai.com
17. ↑ISO 27001: docs.retellai.com
18. ↑PCI DSS: docs.retellai.com
19. ↑Published SLA: docs.retellai.com · retellai.com
20. ↑Rate limits: docs.retellai.com · docs.retellai.com
21. ↑Known restrictions: retellai.com · docs.retellai.com

Every field change, who made it, and when - from our audited data pipeline and editors.

1. 2026-06-21 Capabilities: {} → {"byo_models":true,"outbound_calling":true,"telephony_included":true}
2. 2026-06-21 Summary Md: (none) → Retell AI is a voice agent platform for automating phone calls, supporting both…
3. 2026-06-21 Score Pricing Transparency: (none) → 85
4. 2026-06-21 Score Setup Speed: (none) → 60
5. 2026-06-21 Score Docs Quality: (none) → 35
6. 2026-06-21 Score Procurement Friction: (none) → 85
7. 2026-06-21 Score Trust Readiness: (none) → 75
8. 2026-06-21 Best For: (none) → Regulated or enterprise workloads - compliance attestations and an enterprise p…
9. 2026-06-21 Scoring Methodology: (none) → Scores are computed deterministically from this profile's published, sourced fi…
10. 2026-06-21 Avoid If: (none) → You want to try it free before paying
11. 2026-06-21 Score Agent Friendliness: (none) → 65
12. 2026-06-21 Changelog URL: (none) → https://www.retellai.com/changelog
13. 2026-06-21 Llms Txt Present: (none) → Yes
14. 2026-06-21 Llms Txt URL: (none) → https://www.retellai.com/llms.txt
15. 2026-06-21 Rendering: (none) → static
16. 2026-06-21 Has Structured Data: (none) → Yes
17. 2026-06-21 Robots Allows Agents: (none) → Yes
18. 2026-06-21 Status Page URL: (none) → https://status.retellai.com
19. 2026-06-21 Docs URL: (none) → https://docs.retellai.com/general/introduction
20. 2026-06-21 Has Published Pricing: set to Yes
21. 2026-06-21 Free Tier Available: set to No
22. 2026-06-21 Free Tier Details: set to $10 one-time trial credit on sign-up (not a recurring free tier)
23. 2026-06-21 Self Serve Signup: set to Yes
24. 2026-06-21 Requires Sales Call: set to No
25. 2026-06-21 Enterprise Plan Available: set to Yes
26. 2026-06-21 SOC 2: set to type_2
27. 2026-06-21 HIPAA: set to Yes
28. 2026-06-21 GDPR: set to Yes
29. 2026-06-21 ISO 27001: set to No
30. 2026-06-21 PCI DSS: set to No
31. 2026-06-21 SLA Published: set to Yes
32. 2026-06-21 SLA URL: set to https://www.retellai.com/legal/terms-of-service
33. 2026-06-21 Data Retention Policy URL: set to https://docs.retellai.com/accounts/data-retention
34. 2026-06-21 Documented Rate Limits: set to Pay-as-you-go plan includes 20 free concurrent calls; additional concurrent cal…
35. 2026-06-21 Rate Limit Requests: set to 20
36. 2026-06-21 Rate Limit Window: set to concurrent calls
37. 2026-06-21 Known Restrictions: set to Services not currently operational within the EU (GDPR compliant via AWS but US…
38. 2026-06-21 Auth Methods: set to api_key
39. 2026-06-21 Auth Docs URL: set to https://docs.retellai.com/accounts/api-keys-overview
40. 2026-06-21 API Style: set to rest
41. 2026-06-21 API Version: set to v2
42. 2026-06-21 Versioning Scheme: set to url
43. 2026-06-21 Stability: set to ga
44. 2026-06-21 Deprecation Policy URL: set to https://docs.retellai.com/deprecation-notice/5-30
45. 2026-06-21 MCP URL: set to https://mcp.retellai.com
46. 2026-06-21 Quickstart URL: set to https://docs.retellai.com/get-started/quick-start
47. 2026-06-21 Idempotency Supported: set to No
48. 2026-06-21 Error Format: set to vendor-specific JSON: {"status": "error", "message": "..."}
49. 2026-06-21 Webhook Signing: set to hmac_sha256
50. 2026-06-21 Webhook Events URL: set to https://docs.retellai.com/features/webhook

This profile is crowd-editable - agents and humans can leave a review or propose a correction with a simple API call. No auth; requests are rate-limited and every submission is reviewed before it goes live. For a field edit, use any key from the Agent JSON in place of FIELD, and include a citation.

curl -X POST https://apio.sh/api/feedback/retell-ai \
  -H 'Content-Type: application/json' \
  -d '{"kind":"review","rating":5,"body":"Your experience with this API…"}'

curl -X POST https://apio.sh/api/suggest/retell-ai/FIELD \
  -H 'Content-Type: application/json' \
  -d '{"value":"corrected value","citations":[{"url":"https://source.example/page","excerpt":"supporting quote"}],"note":"what changed and why"}'

All the ways to contribute →