Compare realtime APIs
Pick up to four APIs from any category and see them side by side.
| OpenAI Realtime API (image input) OpenAI | Synthesia Interactive Avatars Synthesia | Odyssey API (interactive world model video) Odyssey | |
|---|---|---|---|
| Category | Avatars + video | Avatars + video | Avatars + video |
| Status | GA | GA | Beta |
| Est. per minute | n/a | n/a | n/a |
| How that was worked out | Depends on tokens per image (detail level, size) which we did not verify for realtime models | No published realtime rate found | No public price list found; pricing page 404s |
| Pricing model | per-minute | subscription | subscription |
| Free tier | None. | None found for interactive avatars. | Free accounts get 5 concurrent streams; hour quota not published. |
| Connects by | WebRTC, WebSocket | LiveKit | WebRTC, WebSocket |
| Audio in | Speech | Your LiveKit agent's TTS audio | None |
| Audio out | Speech | Your TTS | Not documented |
| Languages | See voice segment. | Not captured. | Text prompts. |
| Latency (vendor claim) | See voice segment. | Not captured. | Third-party reports about 20-22 fps at 720p (frame every ~50 ms); no official latency figure. |
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| High-severity warnings |
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| Compliance | OpenAI API terms; see voice segment. | Not verified in this pass. | Not verified. |
| Self-hostable | No | No | No |
| Last checked | 2026-10-10 | 2026-10-10 | 2026-10-10 |
| Key numbers and features | |||
| Session $/min | - | - | - |
| Entry plan $/mo | $0 | $89 | - |
| Free tier | No | No | Yes |
| Free credit $ | - | - | - |
| Custom avatar | - | - | - |
| From photo | - | - | - |
| Own LLM | - | Yes | - |
| Own voice | - | Yes | - |
| Interrupts | - | - | - |
| Resolution p | - | - | 720 |
| FPS | - | - | 20 |
| CPU only | - | - | - |
| Latency ms | - | - | - |
| Languages | - | - | - |
| Max session min | - | - | 2.5 |
| Concurrency | - | - | 5 |
| WebRTC | Yes | Yes | Yes |
| WebSocket | Yes | - | Yes |
| Phone / SIP | - | - | - |
| HIPAA | - | - | - |
| SOC 2 | - | - | - |
| EU data | - | - | - |
| Self-host | No | No | No |
| Open weights | No | No | No |
| High warnings | 0 | 1 | 1 |