Model comparison
Claude Fable 5.1 vs GPT-5 Pro
Claude Fable 5.1 is the stronger model overall, scoring 69.0 to 46.4 on the Noometry Index.
Last verified . 7 shared benchmarks.
Summary
- They share 7 benchmarks with published results for both. Claude Fable 5.1 scores higher in 4 categories and GPT-5 Pro in 0 categories; 4 gaps are clear of the uncertainty.
- The widest gap is in math, where Claude Fable 5.1 leads 89.6 to 48.5.
- The biggest single-benchmark swing is ARC-AGI-2: 90% for Claude Fable 5.1 and 18.3% for GPT-5 Pro.
- Claude Fable 5.1 is cheaper at $10 / $50 per million input/output tokens, against $15 / $120 for GPT-5 Pro.
- Claude Fable 5.1 accepts more context: 1M tokens versus 400K.
Side by side
| Claude Fable 5.1 | GPT-5 Pro | |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Noometry Index | 69.0 | 46.4 |
| Released | 2026-09-01 | 2025-10-06 |
| Weights | Proprietary | Proprietary |
| Context window | 1M | 400K |
| Max output | 128K | 272K |
| Input $ / M tokens | $10 | $15 |
| Output $ / M tokens | $50 | $120 |
| Results tracked | 52 | 12 |
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Category by category
Coding Claude Fable 5.1 leads
Claude Fable 5.1: 74.7 (#1), GPT-5 Pro: 44.0 (#80)
| Benchmark | Claude Fable 5.1 | GPT-5 Pro |
|---|---|---|
| WeirdML | 92.9% | 60.4% |
| FrontierCode | 50.9% | — |
| CursorBench | 51.8% | — |
| LMArena WebDev | 1744 | — |
| FrontierSWE | 56.3% | — |
| SciCode | 63.1% | — |
| GSO | 88.2% | — |
| LMArena Coding | 1528 | — |
| MirrorCode | 73.3% | — |
| ALE-Bench | 2,143 | — |
| AlgoTune | — | 1.31 |
Agentic & Tool Use Not comparable
Claude Fable 5.1: 50.7 (#5), GPT-5 Pro: —
| Benchmark | Claude Fable 5.1 | GPT-5 Pro |
|---|---|---|
| APEX-Agents | 68.6% | — |
| Remote Labor Index | 17.9% | — |
| GDP.pdf | 29.6% | — |
| Vending-Bench 2 | 5,422 | — |
Reasoning Claude Fable 5.1 leads
Claude Fable 5.1: 76.7 (#7), GPT-5 Pro: 38.9 (#62)
| Benchmark | Claude Fable 5.1 | GPT-5 Pro |
|---|---|---|
| ARC-AGI-2 | 90% | 18.3% |
| ARC-AGI-1 | 97.5% | 70.2% |
| Epoch Capabilities Index | 164.7 | 150.28 |
| SimpleBench | — | 61.6% |
| Kagi LLM Benchmark | — | 76.8% |
| NYT Connections (extended) | 90% | — |
| CritPt | 31.1% | — |
| Chess Puzzles | 47% | — |
| EnigmaEval | — | 18.8% |
| EBR-Bench | 57.1% | — |
| LMArena Hard Prompts | 1526 | — |
| Mystery Game Puzzles | 58% | — |
| DTBench | 97.6% | — |
| LMCA | 65.5% | — |
Math Claude Fable 5.1 leads
Claude Fable 5.1: 89.6 (#4), GPT-5 Pro: 48.5 (#63)
| Benchmark | Claude Fable 5.1 | GPT-5 Pro |
|---|---|---|
| FrontierMath (Tiers 1-3) | 90.2% | 55.8% |
| FrontierMath Tier 4 | 87.8% | 19.5% |
| OTIS Mock AIME 2024-2025 | 100% | — |
| ProofBench | 100% | — |
| LMArena Math | 1525 | — |
| FrontierMath Erdős | 0% | — |
| FrontierMath Tier 4 (v1) | — | 14.6% |
Knowledge Claude Fable 5.1 leads
Claude Fable 5.1: 69.6 (#6), GPT-5 Pro: 56.7 (#42)
| Benchmark | Claude Fable 5.1 | GPT-5 Pro |
|---|---|---|
| Humanity's Last Exam | 46.5% | 31.6% |
| SimpleQA Verified | 70.8% | — |
| LMArena Expert | 1535 | — |
Multimodal Not comparable
Claude Fable 5.1: 53.9 (#4), GPT-5 Pro: —
| Benchmark | Claude Fable 5.1 | GPT-5 Pro |
|---|---|---|
| LMArena Vision | 1318 | — |
| Blueprint-Bench 2 | 41.9% | — |
| Furniture Assembly | 70% | — |
| LMArena Document | 1513 | — |
Multilingual Not comparable
Claude Fable 5.1: 59.1 (#3), GPT-5 Pro: —
| Benchmark | Claude Fable 5.1 | GPT-5 Pro |
|---|---|---|
| LMArena Non-English | 1507 | — |
| LMArena Chinese | 1586 | — |
| LMArena French | 1525 | — |
| LMArena German | 1500 | — |
| LMArena Japanese | 1543 | — |
| LMArena Korean | 1534 | — |
| LMArena Russian | 1521 | — |
| LMArena Spanish | 1516 | — |
Instruction Following Not comparable
Claude Fable 5.1: 79.2 (#6), GPT-5 Pro: —
| Benchmark | Claude Fable 5.1 | GPT-5 Pro |
|---|---|---|
| LMArena Instruction Following | 1517 | — |
Long Context Not comparable
Claude Fable 5.1: 46.7 (#20), GPT-5 Pro: —
| Benchmark | Claude Fable 5.1 | GPT-5 Pro |
|---|---|---|
| LMArena Longer Query | 1522 | — |
Writing & Preference Not comparable
Claude Fable 5.1: 79.2 (#2), GPT-5 Pro: —
| Benchmark | Claude Fable 5.1 | GPT-5 Pro |
|---|---|---|
| LMArena Text | 1510 | — |
| LMArena Creative Writing | 1507 | — |
| EQ-Bench Creative Writing | 2162 | — |
| LMArena Multi-Turn | 1492 | — |
Frequently asked questions
Is Claude Fable 5.1 better than GPT-5 Pro?
Claude Fable 5.1 is the stronger model overall, scoring 69.0 to 46.4 on the Noometry Index.
Which is cheaper, Claude Fable 5.1 or GPT-5 Pro?
Claude Fable 5.1 is cheaper. It lists at $10 per million input tokens and $50 per million output tokens; GPT-5 Pro lists at $15 and $120.
Is Claude Fable 5.1 or GPT-5 Pro better for coding?
Claude Fable 5.1 scores higher on coding benchmarks: 74.7 versus 44.0 in the Noometry coding category.
Which has the bigger context window?
Claude Fable 5.1 does, with 1M tokens against 400K.
How many benchmarks do Claude Fable 5.1 and GPT-5 Pro share?
7 benchmarks have published results for both models. Claude Fable 5.1 has 52 scored results on Noometry and GPT-5 Pro has 12.