OpenAI Realtime API vs Hume AI EVI
How the two platforms compare on pricing, live demos, calls, integrations, and setup — highlighted where they differ.
Developer API
OpenAI Realtime API
Realtime speech-to-speech API for building low-latency voice agents over WebRTC, WebSocket, or SIP.
Voice Agent Platform
Hume AI EVI
Conversational voice platform focused on expressive speech, realtime interaction, and prosody-aware responses.
Highlighted rows differ between these picks
| Attribute | OpenAI Realtime API | Hume AI EVI |
|---|---|---|
| Platform type | Developer API | Voice Agent Platform |
| Pricing | Usage Based pricing $32/M audio input tokens and $64/M audio output tokens for gpt-realtime | $0.04/min $0.04/min for listed EVI usage; external services may add cost |
| Test it | Open live demo | Open live demo |
| Calls | Inbound, Outbound | — |
| Human handoff | Yes | Yes |
| Setup difficulty | Technical | Technical |
| Use cases | Customer Support Appointment Scheduling Lead Qualification Custom Voice Apps | Custom Voice Apps Coaching Education Customer Experience |
| Useful for |
|
|
| Integrations | ||
| Custom tools | ||
| WebRTC | — | |
| WebSocket | — | |
| SIP | — | |
| OpenAI Agents SDK | — | |
| Custom API | — | |
| Web SDK | — | |
| React | — | |
| API | — | |
| LiveKit | — | |
| +1 more across these tools — see each profile for the full list. | ||
Platform type
- OpenAI Realtime API
- Developer API
- Hume AI EVI
- Voice Agent Platform
Pricing
- OpenAI Realtime API
Usage Based pricing
$32/M audio input tokens and $64/M audio output tokens for gpt-realtime
- Hume AI EVI
$0.04/min
$0.04/min for listed EVI usage; external services may add cost
Test it
- OpenAI Realtime API
- Open live demo
- Hume AI EVI
- Open live demo
Calls
- OpenAI Realtime API
- Inbound, Outbound
- Hume AI EVI
- —
Human handoff
- OpenAI Realtime API
- Yes
- Hume AI EVI
- Yes
Setup difficulty
- OpenAI Realtime API
- Technical
- Hume AI EVI
- Technical
Use cases
- OpenAI Realtime API
- Customer SupportAppointment SchedulingLead QualificationCustom Voice Apps
- Hume AI EVI
- Custom Voice AppsCoachingEducationCustomer Experience
Useful for
- OpenAI Realtime API
- • Developer teams
- • Speech-to-speech agents
- • Tool-using voice workflows
- • Custom web and phone experiences
- Hume AI EVI
- • Expressive voice experiences
- • Developer teams
- • Interactive applications
- • Custom web and mobile agents
Integrations
| OpenAI Realtime API | Hume AI EVI | |
|---|---|---|
| Custom tools | ||
| WebRTC | — | |
| WebSocket | — | |
| SIP | — | |
| OpenAI Agents SDK | — | |
| Custom API | — | |
| Web SDK | — | |
| React | — | |
| API | — | |
| LiveKit | — |
+1 more across these tools — see each profile for the full list.
What would these cost to run?
Enter your call volume once and see OpenAI Realtime API and Hume AI EVI priced at the same usage, ranked alongside every other platform.