Gemini 3.1 Flash Live PreviewvsGrok Voice 3.0

Grok Voice 3.0 is more reliable, by 19.5 points. Gemini 3.1 Flash Live Preview passed 51 of 82 scenarios on all three runs, and Grok Voice 3.0 passed 67. A scenario only counts when every run of it passed.

For a voice agent, Grok Voice 3.0, since it gets more scenarios right on every run. Grok Voice 3.0 is ahead on reliability, success rate, agent responses, data accuracy, calls where the agent went quiet and response time, and Gemini 3.1 Flash Live Preview on cost. The two tie on interruption.

Grok Voice 3.0, by 8.1 points. Gemini 3.1 Flash Live Preview saved everything exactly right on 79.2% of the calls that save data, and Grok Voice 3.0 on 87.3%. On Booking calls, 96.5% against 98.2%. On Medicare calls, 34.8% against 59.1%. A call counts only when nothing is missing, wrong, extra or saved twice.

No. Grok Voice 3.0 starts replying 1.54s sooner at the median. Gemini 3.1 Flash Live Preview takes 2.88s at the median and 4.00s at p90; Grok Voice 3.0 takes 1.34s and 1.62s. Both are measured on the call audio, from the caller finishing to the agent starting to reply.

They score the same. Gemini 3.1 Flash Live Preview scores 4.98 and Grok Voice 3.0 4.98 for how well the agent handled being talked over.

Grok Voice 3.0, by 3.3 points. The agent went quiet for 10 seconds or more on 3.3% of Gemini 3.1 Flash Live Preview calls and 0.0% of Grok Voice 3.0 calls.

Gemini 3.1 Flash Live Preview is $0.010 cheaper a minute. Gemini 3.1 Flash Live Preview costs $0.070 a minute of call and Grok Voice 3.0 $0.080, at each vendor's published rates.

Cekura ran both as the whole agent in the same open-source Pipecat pipeline, with the same prompt, tools and connection. A simulated caller worked through all 82 scenarios on live calls, three times each, 3,198 calls across the benchmark. A call passes only when the agent said the right things and saved the right data.