Retell AI vs Deepgram Voice Agent API

Retell AI9.4Visit Deepgram Voice Agent API9.0Visit

Higher score Retell AI #1 in AI Voice Agents 9.4/10 Paid ✓ 4 of 4 features Visit Retell AI

vs

Deepgram Voice Agent API #5 in AI Voice Agents 9.0/10 Paid ✓ 4 of 4 features Visit Deepgram

• Retell AI fits best

  Teams needing practical phone automation quickly

• Deepgram Voice Agent API fits best

  Developers building customizable voice infrastructure

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Side by side

Feature	Retell AI 9.4/10 Visit ↗	Deepgram Voice Agent API 9.0/10 Visit ↗
At a glance
Editor score	9.4	9.0
Ranking	#1 in AI Voice Agents	#5 in AI Voice Agents
Best for	Teams needing practical phone automation quickly	Developers building customizable voice infrastructure
Pricing model	Paid	Paid
Starting price	$0.07 usage-based	$0.06 usage-based
Free plan	—	—
Free trial	—	—
Deployment	Cloud	Cloud, Self-hosted
Platforms	Web	Web
Integrations	12 integrations	11 integrations
Features Retell AI 4/4 · Deepgram Voice Agent API 4/4
Inbound calls	✓	✓
Outbound calls	✓	✓
Human handoff	✓	✓
Custom phone numbers	✓	✓
Specs
Supported languages	55 languages	Not checked yet
Concurrent calls	20 calls	45 calls (best)
Our review
Pros	Handles inbound calls, outbound campaigns, IVR, and DTMF navigation Transfers callers with transcript context and supports knowledge-base responses Includes analytics, transcripts, simulation testing, and CRM integrations	One WebSocket pipeline combines speech recognition, LLM processing and speech output. Choose LLM and TTS providers, with function calling and turn-taking controls. Supports inbound and outbound telephony plus self-hosted deployment.
Cons	Usage-based pricing can vary by model, voice, telephony, and add-ons Enterprise features such as SSO and role-based access require custom pricing The platform is focused on business phone operations rather than general voice use	Requires development work to configure and build voice-agent applications. Per-minute pricing varies by tier and provider choices. Custom - BYO LLM + TTS has no listed per-minute rate.
Our verdict	Retell AI is a platform for building, testing, deploying, and monitoring AI voice agents for business phone operations. It supports inbound call answering, outbound batch calling, appointment booking, record updates, IVR navigation, DTMF… Read the review →	Deepgram Voice Agent API gives developers a streaming foundation for real-time voice applications, combining speech-to-text, LLM orchestration and text-to-speech over a single WebSocket connection. It is aimed at developers and enterprises… Read the review →

Strengths and trade-offs

• Retell AI — where it wins

  • Handles inbound calls, outbound campaigns, IVR, and DTMF navigation
  • Transfers callers with transcript context and supports knowledge-base responses
  • Includes analytics, transcripts, simulation testing, and CRM integrations

  Where it doesn't

  • Usage-based pricing can vary by model, voice, telephony, and add-ons
  • Enterprise features such as SSO and role-based access require custom pricing
  • The platform is focused on business phone operations rather than general voice use

• Deepgram Voice Agent API — where it wins

  • One WebSocket pipeline combines speech recognition, LLM processing and speech output.
  • Choose LLM and TTS providers, with function calling and turn-taking controls.
  • Supports inbound and outbound telephony plus self-hosted deployment.

  Where it doesn't

  • Requires development work to configure and build voice-agent applications.
  • Per-minute pricing varies by tier and provider choices.
  • Custom - BYO LLM + TTS has no listed per-minute rate.

• Retell AI9.4/10 · Paid

  Practical inbound and outbound phone automation with transfers, testing, and analytics.

  Visit Retell AIFull verdict →
• Deepgram Voice Agent API9.0/10 · Paid

  A configurable voice-agent stack with provider choice, telephony and self-hosting.

  Visit DeepgramFull verdict →