Compare / Gemini 3 Flash Preview vs GPT-6 Astra
Gemini 3 Flash Preview vs GPT-6 Astra
5 results from 2 sources that measured both models. Each row is in the source's own units; there is no overall winner.
| Benchmark | Metric | Gemini 3 Flash Preview | GPT-6 Astra |
|---|---|---|---|
| UGI Leaderboardreported | Requested-length error% off the requested word count | 16.0% | 0.0% |
| UGI Leaderboardreported | Style adherencescore from 0 to 1 | 0.37 | 0.38 |
| UGI Leaderboardreported | Writing scorescore out of 100 | 67.7 | 68.9 |
| Vectara Hallucination Leaderboardreported | Answer rate% of documents | 99.8% | 100.0% |
| Vectara Hallucination Leaderboardreported | Hallucination rate% of summaries | 13.5% | 8.7% |
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.