Compare / Claude Opus 4.8 vs grok-4-fast-reasoning
Claude Opus 4.8 vs grok-4-fast-reasoning
17 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 4.8 | grok-4-fast-reasoning |
|---|---|---|---|
| Arena (formerly LMArena)reported | OverallArena rating | 1,469 | 1,417 |
| Arena (formerly LMArena)reported | Business, management and financeArena rating | 1,490 | 1,403 |
| Arena (formerly LMArena)reported | Creative writingArena rating | 1,467 | 1,383 |
| Arena (formerly LMArena)reported | Expert promptsArena rating | 1,525 | 1,421 |
| Arena (formerly LMArena)reported | Instruction followingArena rating | 1,491 | 1,389 |
| Arena (formerly LMArena)reported | OverallArena rating | 1,480 | 1,405 |
| Arena (formerly LMArena)reported | Writing, literature and languageArena rating | 1,474 | 1,388 |
| Artificial Analysisreported | Artificial Analysis Intelligence Indexindex score | 41.8 | 17.9 |
| Artificial Analysisreported | GPQA Diamond% of questions | 92.0% | 84.7% |
| Artificial Analysisreported | Humanity's Last Exam% of questions | 48.7% | 19.1% |
| Artificial Analysisreported | IFBench% of instructions | 62.2% | 50.5% |
| Artificial Analysisreported | Long-context reasoning (AA-LCR)% of questions | 77.7% | 73.7% |
| Artificial Analysisreported | Terminal-Bench Hard% of tasks | 58.3% | 18.9% |
| Artificial Analysisreported | Τ²-bench telecom% of tasks | 94.4% | 65.8% |
| UGI Leaderboardreported | Requested-length error% off the requested word count | 6.0% | 23.0% |
| UGI Leaderboardreported | Style adherencescore from 0 to 1 | 0.40 | 0.33 |
| UGI Leaderboardreported | Writing scorescore out of 100 | 65.9 | 53.4 |
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.