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Gemini 3.1 Flash Live Preview vs GPT Realtime 2.1 Mini

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Gemini 3.1 Flash Live PreviewGoogle
Wins 4 of 8
Reliability
62.2%
Response time
2.88s
Cost / min
$0.0703
GPT Realtime 2.1 MiniOpenAI
Wins 4 of 8
Reliability
50.0%
Response time
2.08s
Cost / min
$0.0202

Gemini 3.1 Flash Live Preview is ahead on reliability, success rate, agent responses and data accuracy, and GPT Realtime 2.1 Mini on calls where the agent went quiet, interruption, response time and cost.

Last updated Methodology by Dileep Chagam

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Gemini 3.1 Flash Live PreviewGPT Realtime 2.1 Mini
  • Reliability62.2%50.0%
  • Success rate76.0%61.4%
  • Agent responses95.9%93.5%
  • Data accuracy79.2%64.5%
  • Went quiet3.3%2.5%
  • Interruption4.984.99
  • Response time2.88s2.08s
  • Cost / min$0.0703$0.0202

Reliability on booking and Medicare calls

Scenarios the agent passed on every one of its 3 runs.

Booking callsMedicare calls
  1. 83%
    9%
    Gemini 3.1 Flash Live Preview
  2. 68%
    4%
    GPT Realtime 2.1 Mini

Related comparisons

Both providers, every model: Google vs OpenAI

Each model on its own: Gemini 3.1 Flash Live Preview and GPT Realtime 2.1 Mini

Gemini 3.1 Flash Live Preview vs GPT Realtime 2.1 Mini FAQ

  • Gemini 3.1 Flash Live Preview is more reliable, by 12.2 points. Gemini 3.1 Flash Live Preview passed 51 of 82 scenarios on all three runs, and GPT Realtime 2.1 Mini passed 41. A scenario only counts when every run of it passed.

  • For a voice agent, Gemini 3.1 Flash Live Preview, since it gets more scenarios right on every run. Gemini 3.1 Flash Live Preview is ahead on reliability, success rate, agent responses and data accuracy, and GPT Realtime 2.1 Mini on calls where the agent went quiet, interruption, response time and cost.

  • Gemini 3.1 Flash Live Preview, by 14.7 points. Gemini 3.1 Flash Live Preview saved everything exactly right on 79.2% of the calls that save data, and GPT Realtime 2.1 Mini on 64.5%. On Booking calls, 96.5% against 88.8%. On Medicare calls, 34.8% against 0.0%. A call counts only when nothing is missing, wrong, extra or saved twice.

  • No. GPT Realtime 2.1 Mini starts replying 0.80s sooner at the median. Gemini 3.1 Flash Live Preview takes 2.88s at the median and 4.00s at p90; GPT Realtime 2.1 Mini takes 2.08s and 2.75s. Both are measured on the call audio, from the caller finishing to the agent starting to reply.

  • GPT Realtime 2.1 Mini, by 0.01 on a 0 to 5 scale. Gemini 3.1 Flash Live Preview scores 4.98 and GPT Realtime 2.1 Mini 4.99 for how well the agent handled being talked over.

  • GPT Realtime 2.1 Mini, by 0.8 points. The agent went quiet for 10 seconds or more on 3.3% of Gemini 3.1 Flash Live Preview calls and 2.5% of GPT Realtime 2.1 Mini calls.

  • GPT Realtime 2.1 Mini is $0.0501 cheaper a minute. Gemini 3.1 Flash Live Preview costs $0.0703 a minute of call and GPT Realtime 2.1 Mini $0.0202, 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, 3,690 calls across the benchmark. A call passes only when the agent said the right things and saved the right data.

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