Back to Voice & realtime
Model comparison
Gemini 3.8 Live vs Grok Voice Think Fast 2.0
Compare Gemini 3.8 Live and Grok Voice Think Fast 2.0 using the same provider-sourced voice & realtime rubric. No mystery score and no invented benchmark ranking.
Quick take
Gemini 3.8 Live
Google's real-time voice model for responsive conversations with audio, text and visual context.
Best for
- Conversational customer support
- Voice assistants with camera context
- Everyday tool-using voice agents
Watch out for
Audio input and output are charged separately, not as one flat call-minute price. Text, visual context, thinking and search can add to the bill.
Grok Voice Think Fast 2.0
SpaceXAI's current realtime speech-to-speech model for sub-second conversational agents with tool access.
Best for
- Realtime voice agents with tools
- Minute-based call-cost planning
- Teams using SpaceXAI's model and search stack
Watch out for
The model-specific price is higher than the generic 'starting at' Voice API headline. Use the Think Fast 2.0 row when budgeting.
Compare the published facts
Gemini 3.8 Live vs Grok Voice Think Fast 2.0
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 | Gemini 3.8 Live | Grok Voice Think Fast 2.0 |
|---|---|---|
| Price basisToken-, character-, or minute-based price for the listed access route. | Audio $0.005/min in · $0.018/min out | $0.08 / audio minute |
| Interaction modeSpeech-to-speech, audio-to-audio, or streamed text-to-speech behavior. | Speech-to-speech with visual input and interleaved reasoning | Realtime speech-to-speech with tools |
| Published latencyProvider-published measurement with its stated exclusions; not a Cody test. | Not published | Sub-second provider claim |
| LanguagesProvider-documented language coverage or a clear unpublished marker. | 97 languages (Google launch claim) | Exact supported list not published here |
| Tools & controlNative function calling, reasoning, or speech-control features. | Functions (async by default), search grounding | Realtime tool use |
| Context or input limitDocumented token or character limit where it is meaningful. | 131,072 input · 65,536 output | Not published |
How to choose
Compare the job, not the hype.
Start with the job you need to complete, then validate cost, access, and policy details on your exact provider route.
Gemini 3.8 Live
Google says paid Gemini API prompts and responses are not used to improve its products. Unpaid-service content generally may be used, with different treatment for EEA, UK, and Swiss users; check the current terms for your account and region.
Provider and API links
Grok Voice Think Fast 2.0
SpaceXAI says it does not train on API inputs or outputs without explicit permission. Default encrypted retention is 30 days; team-level zero data retention is available with feature tradeoffs.
Provider and API links
Frequently asked questions
Gemini 3.8 Live vs Grok Voice Think Fast 2.0 FAQ
What is the main difference between Gemini 3.8 Live and Grok Voice Think Fast 2.0?
Gemini 3.8 Live: Google's real-time voice model for responsive conversations with audio, text and visual context. Grok Voice Think Fast 2.0: SpaceXAI's current realtime speech-to-speech model for sub-second conversational agents with tool access.
Should I choose Gemini 3.8 Live or Grok Voice Think Fast 2.0?
Consider Gemini 3.8 Live when your priority is Conversational customer support. Consider Grok Voice Think Fast 2.0 when your priority is Realtime voice agents with tools. Test both with your own data and provider route before committing.
Is this Gemini 3.8 Live vs Grok Voice Think Fast 2.0 comparison based on Cody benchmarks?
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.