Compare / gemini-3-pro-preview vs GPT-5.1
gemini-3-pro-preview vs GPT-5.1
6 results from 3 sources that measured both models. Each row is in the source's own units; there is no overall winner.
| Benchmark | Metric | gemini-3-pro-preview | GPT-5.1 |
|---|---|---|---|
| UGI Leaderboardreported | Requested-length error% off the requested word count | 33.0% | 113.0% |
| UGI Leaderboardreported | Style adherencescore from 0 to 1 | 0.37 | 0.38 |
| UGI Leaderboardreported | Writing scorescore out of 100 | 66.7 | 55.8 |
| Vectara Hallucination Leaderboardreported | Answer rate% of documents | 99.4% | 100.0% |
| Vectara Hallucination Leaderboardreported | Hallucination rate% of summaries | 13.6% | 10.9% |
| Vending-Bench 2reported | Money after a yearUS dollars | $5,478.16 | $1,473.43 |
Bold green marks the better value on that metric. Where a source reports ranges that overlap, the difference may not be meaningful; see the benchmark page for ranges.