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Retell AI vs Vapi

Two fact sheets from our own research, side by side — pricing, platforms, API access and status re-checked by us rather than quoted from the vendors. Retell AI starts at $0.07, Vapi at $0.05. Only Retell AI has a free tier. Both ship a public API.

Side by side

FactRetell AIVapi
CategoryVoice Agents & Phone AIVoice Agents & Phone AI
Pricing modelFreemiumPaid
Starts at$0.07 minute$0.05 minute
Public APIYesYes
PlatformsWeb, APIWeb, API
CompanyRetell AI Inc.Vapi Inc.
Launched20232020
Last verifiedSep 6, 2026Sep 6, 2026

What our research says

Retell AI

One of the more honest voice-agent stacks: the pricing page breaks out infrastructure, TTS and LLM cost per minute so you can predict a call's cost instead of guessing. Telephony choice is wide and the concurrency allowance is generous. The catch is that per-minute billing plus add-ons makes a busy contact centre expensive fast, and the cheap end of the range only holds if you pick the cheap models.

Pros

  • Per-minute cost broken down by voice infrastructure, TTS provider and LLM on the public pricing page
  • Telephony via SIP trunking, Twilio and Vonage plus n8n, HubSpot, Make and Go High Level integrations
  • 20 concurrent calls included before any concurrency charge
  • Voice, chat and SMS agents share one platform and API
  • HIPAA path exists via a signed BAA covered in the terms of service

Cons

  • Cost per minute more than quadruples between the cheapest and most capable model combinations
  • Knowledge base, denoising, PII removal and branded caller ID are all metered extras
  • No flat-rate plan, so a spike in call volume lands straight on the invoice

Vapi

The default answer when a developer needs a voice agent on a phone line rather than a chat widget: it handles the hard real-time parts — barge-in, latency, turn-taking, telephony — and lets you swap in your own models. Enterprise adoption at Ring and Intuit is real validation. Cost forecasting is the hard part, because the platform fee is only one of four meters running.

Pros

  • Handles real-time voice mechanics: turn-taking, interruptions, latency and telephony
  • Bring-your-own-key support across OpenAI, Anthropic and Google avoids double model markup
  • CRM and helpdesk integrations for Salesforce, HubSpot and Zendesk
  • SOC 2, HIPAA and PCI compliance plus SSO and RBAC on the enterprise tier
  • Proven at scale, with Amazon Ring routing inbound support volume through it

Cons

  • The $0.05/minute platform fee sits on top of speech, model and voice provider costs
  • Concurrency beyond ten lines costs $10 per line per month
  • Enterprise compliance features require an annual Scale contract
  • It is a developer platform, so there is no usable no-code path

Which one fits

Choose Retell AI if you need

  • Teams replacing an outbound qualification or booking script
  • Contact centres that already have Twilio, Vonage or SIP trunking
  • Developers who want per-minute cost visibility before launch

Choose Vapi if you need

  • Developers building phone-based support, booking or qualification agents
  • Replacing IVR trees with something that actually listens
  • Teams that want to bring their own model and voice provider keys

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