Retell AI vs Vapi
A side-by-side comparison of Retell AI and Vapi, two Voice tools, drawn from Ignaite's continuously-verified listings.
Compared from listings verified as of
At a glance
| Attribute | Retell AI | Vapi |
|---|---|---|
| Category | Voice | Voice |
| Pricing | FREEMIUM | FREEMIUM |
| License | Proprietary | Proprietary |
| Deployment | Cloud | Cloud |
| Platforms (differs) | Web, API | API, Web |
| Model support | Multi-model | Multi-model |
| Vendor (differs) | Retell AI | Vapi |
| Capabilities (differs) |
|
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The honest brief
Retell AI
Bring your own LLM behind the voice agent, so it isn't locked to a single model like most all-in-one voice platforms.
- Inbound and outbound call handling
- SIP/Twilio telephony built in
- Low-latency turn-taking model
- No-code builder plus API
- Per-minute costs stack with LLM/TTS
- Voice quality depends on chosen vendors
- Cloud-only, no self-host
Vapi
Solves the hard parts of phone agents — telephony, low-latency turn-taking and barge-in — while leaving STT/LLM/TTS fully pluggable.
- Telephony and interrupts handled
- Pluggable STT + LLM + TTS stack
- Fast to a working phone agent
- Generous developer free tier
- Per-minute costs stack across layers
- Latency depends on chosen models
- Complex configuration surface
- Cloud-only orchestration
When to pick which
Both cover Voice agent and Tool / function calling.
Pick Retell AI if you need AI app builder.
- AI app builder (primary capability)
Pick Vapi if you need Multi-model access.
- Multi-model access (secondary capability)