Compare / Claude Opus 4.1 vs GPT-5 Nano
Claude Opus 4.1 vs GPT-5 Nano
15 results from 3 sources that measured both models. Each row is in the source's own units; there is no overall winner.
| Benchmark | Metric | Claude Opus 4.1 | GPT-5 Nano |
|---|---|---|---|
| Arena (formerly LMArena)reported | Business, management and financeArena rating | 1,447 | 1,339 |
| Arena (formerly LMArena)reported | Creative writingArena rating | 1,445 | 1,247 |
| Arena (formerly LMArena)reported | Expert promptsArena rating | 1,482 | 1,354 |
| Arena (formerly LMArena)reported | Instruction followingArena rating | 1,458 | 1,327 |
| Arena (formerly LMArena)reported | OverallArena rating | 1,450 | 1,338 |
| Arena (formerly LMArena)reported | Writing, literature and languageArena rating | 1,446 | 1,289 |
| Artificial Analysisreported | Artificial Analysis Intelligence Indexindex score | 22.8 | 13.0 |
| Artificial Analysisreported | GPQA Diamond% of questions | 80.9% | 67.6% |
| Artificial Analysisreported | Humanity's Last Exam% of questions | 12.5% | 9.5% |
| Artificial Analysisreported | IFBench% of instructions | 55.4% | 67.6% |
| Artificial Analysisreported | Long-context reasoning (AA-LCR)% of questions | 76.0% | 45.0% |
| Artificial Analysisreported | Terminal-Bench Hard% of tasks | 34.3% | 17.4% |
| Artificial Analysisreported | Τ²-bench telecom% of tasks | 71.4% | 36.5% |
| Vectara Hallucination Leaderboardreported | Answer rate% of documents | 92.4% | 100.0% |
| Vectara Hallucination Leaderboardreported | Hallucination rate% of summaries | 11.8% | 10.5% |
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.