Claude Fable 5.1 vs Grok 4
Claude Fable 5.1 
Grok 4 Verdict
- Claude Fable 5.1 leads on quality: 70.7 vs 58.6.
- Claude Fable 5.1 is stronger in agents & tools, coding, composite, knowledge, long context.
- Grok 4 is stronger in human preference, instruction following, maths, multimodal, reasoning.
- Grok 4 is 13× cheaper ($1.56 vs $20.00 per 1M blended).
| Metric | Claude Fable 5.1 | Grok 4 |
|---|---|---|
| BenchLeader Index | 70.7 | 58.6 |
| Agents & tools score | 72.1 | 55.3 |
| Coding score | 68.5 | 61.2 |
| Composite score | 95.0 | 57.4 |
| Knowledge score | 70.5 | 58.3 |
| Long context score | 69.3 | 69.0 |
| Human preference score | – | 59.8 |
| Instruction following score | – | 62.4 |
| Maths score | – | 58.0 |
| Multimodal score | – | 53.8 |
| Reasoning score | – | 58.3 |
| Blended price $/M | $20.00 | $1.56 |
| Output speed | 65 tok/s | – |
| Time to first answer | 295.0 s | – |
| Context window | 1M | 256k |
| GPQA Diamond | – | 87.0% |
| OTIS Mock AIME | – | 84.0% |
| Terminal-Bench | – | 27.2% |
| SimpleBench | – | 60.5% |
| Fiction.LiveBench 120k | – | 96.9% |
| Cybench | – | 43.0% |
| WeirdML | – | 45.7% |
| APEX-Agents | 47.4% | 15.2% |
| Epoch Capabilities Index | 164.2 | 146.4 |
| LMArena Text | – | 1411 |
| LMArena Hard Prompts | – | 1420 |
| LMArena Coding | – | 1435 |
| LMArena Vision | – | 1210 |
| AA Intelligence Index | 53.4 | 22.5 |
| IFBench | – | 53.7% |
| AA-LCR | 85.3% | 68.0% |
| MMMU-Pro | – | 68.8% |
| AA-Omniscience | 43.5 | 2.1 |
| Terminal-Bench Hard | – | 37.9% |
| GPQA Diamond (AA) | 93.7% | 87.7% |
| Humanity's Last Exam (AA) | 59.1% | 26.7% |
| SciCode (AA) | 63.1% | – |
| τ²-Bench Telecom (AA) | – | 74.8% |
| AIME (Vals) | – | 90.6% |
| LiveCodeBench | 90.5% | 83.3% |
| MMLU-Pro | 92.4% | 85.3% |
| IOI | 90.8% | – |
| LegalBench | 88.5% | 83.2% |
| CorpFin | – | 66.0% |
| TaxEval | 76.0% | 65.1% |
| MedQA | – | 92.5% |
| MGSM | – | 90.9% |
| Terminal-Bench 2.1 (Vals) | 85.0% | – |
| SWE-bench (Vals) | – | 57.8% |
| GPQA Diamond (Vals) | 93.4% | 88.1% |
| Vals Index | 68.8 | – |
| IMO 2025 | – | 21.4% |
| MathArena Apex | – | 2.1% |
| MCP Atlas | 87.2% | – |
| PRBench Finance | 50.8% | – |
| PRBench Legal | 51.6% | – |
| HiL-Bench | 61.5% | – |
| Kagi LLM Benchmark | – | 73.6% |
| IFEval (HELM) | – | 94.9% |
| Omni-MATH (HELM) | – | 60.3% |
| WildBench (HELM) | – | 79.7% |
| MMLU-Pro (HELM) | – | 85.1% |
| GPQA Diamond (HELM) | – | 72.6% |
| HELM Capabilities mean | – | 78.5% |
| Aider Polyglot | – | 79.6% |
| ARC-AGI-1 | – | 79.6% |
| ARC-AGI-2 | – | 29.4% |
| BFCL Overall | – | 63.0% |
Data as of 2026-09-12. Best configuration of each model; every score links to its source on the model pages.
Claude Fable 5.1 vs Grok 4: questions
- Is Claude Fable 5.1 better than Grok 4?
- Claude Fable 5.1 leads on quality: 70.7 vs 58.6. The BenchLeader Index combines every independent quality benchmark; Claude Fable 5.1 is ahead overall as of 2026-09-12, but check the category scores for your use.
- Is Claude Fable 5.1 better than Grok 4 for coding?
- Claude Fable 5.1 scores higher in coding (69 vs 61 on the category index, where 50 is average).
- Is Claude Fable 5.1 better than Grok 4 for agentic tasks?
- Claude Fable 5.1 scores higher in agentic tasks (72 vs 55 on the category index, where 50 is average).
- Which is cheaper, Claude Fable 5.1 or Grok 4?
- Grok 4 is cheaper: $1.56 against $20.00 per million tokens, blended at three input tokens per output token.
- Which has the larger context window?
- Claude Fable 5.1 accepts more context: 1M against 256k tokens.