Model comparison
Claude Fable 5 vs Claude Opus 5.5
Claude Opus 5.5 is the stronger model overall, scoring 68.6 to 66.8 on the Noometry Index.
Last verified . 43 shared benchmarks.
Summary
- They share 43 benchmarks with published results for both. Claude Fable 5 scores higher in 1 category and Claude Opus 5.5 in 9 categories; 9 gaps are clear of the uncertainty.
- The widest gap is in multimodal, where Claude Opus 5.5 leads 57.8 to 45.3.
- The biggest single-benchmark swing is Furniture Assembly: 35.8% for Claude Fable 5 and 83.3% for Claude Opus 5.5.
- Claude Opus 5.5 is cheaper at $4 / $20 per million input/output tokens, against $10 / $50 for Claude Fable 5.
Side by side
| Claude Fable 5 | Claude Opus 5.5 | |
|---|---|---|
| Provider | Anthropic | Anthropic |
| Noometry Index | 66.8 | 68.6 |
| Released | 2026-06-07 | 2026-09-22 |
| Weights | Proprietary | Proprietary |
| Context window | 1M | 1M |
| Max output | 128K | 128K |
| Input $ / M tokens | $10 | $4 |
| Output $ / M tokens | $50 | $20 |
| Results tracked | 62 | 44 |
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Category by category
Coding Claude Opus 5.5 leads
Claude Fable 5: 70.6 (#4), Claude Opus 5.5: 71.9 (#3)
| Benchmark | Claude Fable 5 | Claude Opus 5.5 |
|---|---|---|
| FrontierCode | 53.5% | 54.6% |
| LMArena WebDev | 1625 | 1813 |
| FrontierSWE | 47% | 62.3% |
| SciCode | 61% | 66.9% |
| LMArena Coding | 1519 | 1547 |
| MirrorCode | 63.9% | 77.4% |
| ALE-Bench | 2,041 | 2,147 |
| DeepSWE | 69.9% | — |
| CursorBench | — | 57.8% |
| GSO | 78.4% | — |
| WeirdML | 91.9% | — |
Agentic & Tool Use Claude Fable 5 leads
Claude Fable 5: 54.0 (#2), Claude Opus 5.5: 45.3 (#15)
| Benchmark | Claude Fable 5 | Claude Opus 5.5 |
|---|---|---|
| APEX-Agents | 63.6% | 73.5% |
| GDP.pdf | 30% | 30.6% |
| Vending-Bench 2 | 5,680 | 9,235 |
| Remote Labor Index | 16.1% | — |
| τ²-bench Banking | 39.7% | — |
| PostTrainBench | 41.8% | — |
| GBAEval | 74.5% | — |
| LMArena Search | 1230 | — |
Reasoning Claude Opus 5.5 leads
Claude Fable 5: 76.8 (#6), Claude Opus 5.5: 80.2 (#3)
| Benchmark | Claude Fable 5 | Claude Opus 5.5 |
|---|---|---|
| ARC-AGI-2 | 89.2% | 93.3% |
| NYT Connections (extended) | 92.7% | 88.5% |
| ARC-AGI-1 | 98.5% | 98.5% |
| CritPt | 28.6% | 31.7% |
| EBR-Bench | 39.5% | 71.4% |
| LMArena Hard Prompts | 1508 | 1535 |
| Mystery Game Puzzles | 52% | 71% |
| DTBench | 98.4% | 98.9% |
| LMCA | 61.1% | 68.2% |
| Epoch Capabilities Index | 162.06 | 167.33 |
| SimpleBench | 81.9% | — |
| Kagi LLM Benchmark | 91.4% | — |
| Chess Puzzles | 41% | — |
| EnigmaEval | 39.3% | — |
| Surface Evolver Bench | 95% | — |
| Bench to the Future 3 | 0.13 | — |
Math Claude Opus 5.5 leads
Claude Fable 5: 88.5 (#5), Claude Opus 5.5: 91.8 (#3)
| Benchmark | Claude Fable 5 | Claude Opus 5.5 |
|---|---|---|
| FrontierMath (Tiers 1-3) | 87% | 91.2% |
| FrontierMath Tier 4 | 90.2% | 95% |
| OTIS Mock AIME 2024-2025 | 100% | 100% |
| ProofBench | 95% | 100% |
| LMArena Math | 1519 | 1506 |
| FrontierMath Erdős | 0% | 2.9% |
Knowledge Claude Opus 5.5 leads
Claude Fable 5: 62.2 (#25), Claude Opus 5.5: 66.4 (#10)
| Benchmark | Claude Fable 5 | Claude Opus 5.5 |
|---|---|---|
| GPQA Diamond | 85.9% | 90.6% |
| SimpleQA Verified | 70.7% | 72.2% |
| LMArena Expert | 1534 | 1547 |
Multimodal Claude Opus 5.5 leads
Claude Fable 5: 45.3 (#17), Claude Opus 5.5: 57.8 (#1)
| Benchmark | Claude Fable 5 | Claude Opus 5.5 |
|---|---|---|
| LMArena Vision | 1324 | 1321 |
| Blueprint-Bench 2 | 38.6% | 51.2% |
| Furniture Assembly | 35.8% | 83.3% |
| LMArena Document | 1496 | — |
Multilingual Claude Opus 5.5 leads
Claude Fable 5: 57.3 (#9), Claude Opus 5.5: 59.1 (#2)
| Benchmark | Claude Fable 5 | Claude Opus 5.5 |
|---|---|---|
| LMArena Non-English | 1481 | 1507 |
| LMArena Chinese | 1543 | 1588 |
| LMArena French | 1505 | 1514 |
| LMArena Russian | 1504 | 1520 |
| LMArena Spanish | 1498 | 1507 |
| LMArena German | 1486 | — |
| LMArena Japanese | 1506 | — |
| LMArena Korean | 1488 | — |
Instruction Following Claude Opus 5.5 leads
Claude Fable 5: 78.6 (#8), Claude Opus 5.5: 80.0 (#3)
| Benchmark | Claude Fable 5 | Claude Opus 5.5 |
|---|---|---|
| LMArena Instruction Following | 1502 | 1537 |
Long Context Too close to call
Claude Fable 5: 46.3 (#23), Claude Opus 5.5: 47.1 (#19)
| Benchmark | Claude Fable 5 | Claude Opus 5.5 |
|---|---|---|
| LMArena Longer Query | 1509 | 1532 |
Writing & Preference Claude Opus 5.5 leads
Claude Fable 5: 75.9 (#5), Claude Opus 5.5: 78.2 (#3)
| Benchmark | Claude Fable 5 | Claude Opus 5.5 |
|---|---|---|
| LMArena Text | 1491 | 1515 |
| LMArena Creative Writing | 1494 | 1533 |
| EQ-Bench Creative Writing | 1943 | 2050 |
| LMArena Multi-Turn | 1504 | 1499 |
| EQ-Bench 4 | 1340 | — |
Frequently asked questions
Is Claude Fable 5 better than Claude Opus 5.5?
Claude Opus 5.5 is the stronger model overall, scoring 68.6 to 66.8 on the Noometry Index.
Which is cheaper, Claude Fable 5 or Claude Opus 5.5?
Claude Opus 5.5 is cheaper. It lists at $4 per million input tokens and $20 per million output tokens; Claude Fable 5 lists at $10 and $50.
Is Claude Fable 5 or Claude Opus 5.5 better for coding?
Claude Opus 5.5 scores higher on coding benchmarks: 71.9 versus 70.6 in the Noometry coding category.
Which has the bigger context window?
Both accept 1M tokens.
How many benchmarks do Claude Fable 5 and Claude Opus 5.5 share?
43 benchmarks have published results for both models. Claude Fable 5 has 62 scored results on Noometry and Claude Opus 5.5 has 44.