Compare / Claude Fable 5 vs grok-4-fast-reasoning
Claude Fable 5 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 Fable 5 | grok-4-fast-reasoning |
|---|---|---|---|
| Arena (formerly LMArena)reported | OverallArena rating | 1,483 | 1,417 |
| Arena (formerly LMArena)reported | Business, management and financeArena rating | 1,503 | 1,403 |
| Arena (formerly LMArena)reported | Creative writingArena rating | 1,501 | 1,383 |
| Arena (formerly LMArena)reported | Expert promptsArena rating | 1,550 | 1,421 |
| Arena (formerly LMArena)reported | Instruction followingArena rating | 1,509 | 1,389 |
| Arena (formerly LMArena)reported | OverallArena rating | 1,504 | 1,405 |
| Arena (formerly LMArena)reported | Writing, literature and languageArena rating | 1,508 | 1,388 |
| Artificial Analysisreported | Artificial Analysis Intelligence Indexindex score | 49.6 | 17.9 |
| Artificial Analysisreported | GPQA Diamond% of questions | 92.6% | 84.7% |
| Artificial Analysisreported | Humanity's Last Exam% of questions | 55.5% | 19.1% |
| Artificial Analysisreported | IFBench% of instructions | 63.5% | 50.5% |
| Artificial Analysisreported | Long-context reasoning (AA-LCR)% of questions | 82.3% | 73.7% |
| Artificial Analysisreported | Terminal-Bench Hard% of tasks | 62.9% | 18.9% |
| Artificial Analysisreported | Τ²-bench telecom% of tasks | 98.5% | 65.8% |
| UGI Leaderboardreported | Requested-length error% off the requested word count | 2.0% | 23.0% |
| UGI Leaderboardreported | Style adherencescore from 0 to 1 | 0.41 | 0.33 |
| UGI Leaderboardreported | Writing scorescore out of 100 | 74.2 | 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.