Model comparison
Compare GPT-Live 1 and Inworld Realtime TTS-2 using the same provider-sourced voice & realtime rubric. No mystery score and no invented benchmark ranking.
Facts checked September 11, 2026
Quick take
OpenAI's full-duplex voice frontend for natural conversation that delegates deeper reasoning and actions to a separate backend agent.
Speech interruption does not automatically cancel backend work. Your application still owns permissions, confirmations, cancellation, durable task state, result validation, and playback safeguards.
Inworld's newest expressive realtime text-to-speech model, designed to remember conversational delivery and speak in more than 100 languages.
This is the speech layer, not a complete agent. Inworld's current zero-data-retention page does not explicitly list TTS-2, so confirm coverage before sending sensitive text or voice data.
Compare the published facts
Values use each provider's own published units and limits. A blank means the provider did not publish a directly comparable value in the sources reviewed.
| Voice & realtime | GPT-Live 1 | Inworld Realtime TTS-2 |
|---|---|---|
| Price basisToken-, character-, or minute-based price for the listed access route. | $0.05 / voice minute + backend usage | $25 / 1M chars on demand; volume discounts |
| Interaction modeSpeech-to-speech, audio-to-audio, or streamed text-to-speech behavior. | Full-duplex voice frontend with delegated backend | Steerable realtime TTS with prior-audio context |
| Published latencyProvider-published measurement with its stated exclusions; not a Cody test. | Not published | Under 200ms median TTFA |
| LanguagesProvider-documented language coverage or a clear unpublished marker. | Multiple accents, dialects, and languages; exact list not published | 100+ with mid-utterance switching |
| Tools & controlNative function calling, reasoning, or speech-control features. | Responses or client delegation to backend agents and tools | Voice direction, design, cloning, non-verbals |
| Context or input limitDocumented token or character limit where it is meaningful. | Not published | Not published |
How to choose
Start with the job you need to complete, then validate cost, access, and policy details on your exact provider route.
OpenAI says API content is not used for training by default. Default abuse-monitoring logs may be retained up to 30 days, with additional controls available to qualifying organizations.
Provider and API links
Inworld advertises zero data retention as an enterprise add-on, but its currently published ZDR support page names only TTS-1.5 Mini and Max. Confirm TTS-2 coverage directly before sending regulated or confidential text.
Frequently asked questions
GPT-Live 1: OpenAI's full-duplex voice frontend for natural conversation that delegates deeper reasoning and actions to a separate backend agent. Inworld Realtime TTS-2: Inworld's newest expressive realtime text-to-speech model, designed to remember conversational delivery and speak in more than 100 languages.
Consider GPT-Live 1 when your priority is Natural customer-service and scheduling calls. Consider Inworld Realtime TTS-2 when your priority is Realtime companions and support voices. Test both with your own data and provider route before committing.
No. This comparison aligns provider-published facts for the Voice & realtime category. It does not claim a universal winner or combine incompatible third-party benchmark scores.
