Compare / GPT-5.5 vs grok-3
GPT-5.5 vs grok-3
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 | GPT-5.5 | grok-3 |
|---|---|---|---|
| UGI Leaderboardreported | Requested-length error% off the requested word count | 13.0% | 16.0% |
| UGI Leaderboardreported | Style adherencescore from 0 to 1 | 0.41 | 0.36 |
| UGI Leaderboardreported | Writing scorescore out of 100 | 69.7 | 58.7 |
| Vectara Hallucination Leaderboardreported | Answer rate% of documents | 100.0% | 93.0% |
| Vectara Hallucination Leaderboardreported | Hallucination rate% of summaries | 9.3% | 5.8% |
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.