Compare / Claude Haiku 4.5 vs grok-4-1-fast-reasoning
Claude Haiku 4.5 vs grok-4-1-fast-reasoning
20 results from 4 sources that measured both models. Each row is in the source's own units; there is no overall winner.
| Benchmark | Metric | Claude Haiku 4.5 | grok-4-1-fast-reasoning |
|---|---|---|---|
| Arena (formerly LMArena)reported | OverallArena rating | 1,418 | 1,413 |
| Arena (formerly LMArena)reported | Business, management and financeArena rating | 1,420 | 1,417 |
| Arena (formerly LMArena)reported | Creative writingArena rating | 1,387 | 1,414 |
| Arena (formerly LMArena)reported | Expert promptsArena rating | 1,452 | 1,438 |
| Arena (formerly LMArena)reported | Instruction followingArena rating | 1,415 | 1,401 |
| Arena (formerly LMArena)reported | OverallArena rating | 1,414 | 1,430 |
| Arena (formerly LMArena)reported | Writing, literature and languageArena rating | 1,399 | 1,407 |
| Berkeley Function Calling Leaderboard (BFCL) V4reported | Irrelevance detection% correct | 95.3% | 79.4% |
| Berkeley Function Calling Leaderboard (BFCL) V4reported | Memory% correct | 54.4% | 54.0% |
| Berkeley Function Calling Leaderboard (BFCL) V4reported | Multi-turn tasks% correct | 53.6% | 58.9% |
| Berkeley Function Calling Leaderboard (BFCL) V4reported | Overall accuracy% correct | 68.7% | 69.6% |
| Berkeley Function Calling Leaderboard (BFCL) V4reported | Relevance detection% correct | 62.5% | 81.2% |
| Berkeley Function Calling Leaderboard (BFCL) V4reported | Single-turn calls (curated)% correct | 86.5% | 88.3% |
| Berkeley Function Calling Leaderboard (BFCL) V4reported | Single-turn calls (user-contributed)% correct | 78.7% | 78.5% |
| Berkeley Function Calling Leaderboard (BFCL) V4reported | Web search% correct | 83.5% | 82.5% |
| UGI Leaderboardreported | Requested-length error% off the requested word count | 6.0% | 7.0% |
| UGI Leaderboardreported | Style adherencescore from 0 to 1 | 0.39 | 0.33 |
| UGI Leaderboardreported | Writing scorescore out of 100 | 52.2 | 51.3 |
| Vectara Hallucination Leaderboardreported | Answer rate% of documents | 99.5% | 99.7% |
| Vectara Hallucination Leaderboardreported | Hallucination rate% of summaries | 9.8% | 19.2% |
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.