Compare / R1 vs GPT-5.5
R1 vs GPT-5.5
8 results from 3 sources that measured both models. Each row is in the source's own units; there is no overall winner.
| Benchmark | Metric | R1 | GPT-5.5 |
|---|---|---|---|
| Arena (formerly LMArena)reported | Business, management and financeArena rating | 1,388 | 1,489 |
| Arena (formerly LMArena)reported | Creative writingArena rating | 1,374 | 1,452 |
| Arena (formerly LMArena)reported | OverallArena rating | 1,398 | 1,481 |
| UGI Leaderboardreported | Requested-length error% off the requested word count | 18.0% | 13.0% |
| UGI Leaderboardreported | Style adherencescore from 0 to 1 | 0.30 | 0.41 |
| UGI Leaderboardreported | Writing scorescore out of 100 | 51.8 | 69.7 |
| Vectara Hallucination Leaderboardreported | Answer rate% of documents | 97.0% | 100.0% |
| Vectara Hallucination Leaderboardreported | Hallucination rate% of summaries | 11.3% | 9.3% |
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.