Up to four models
Claude Opus 5.5 vs Claude Fable 5.1
On the index (GPT-4 = 100), Claude Opus 5.5 scores 197 and Claude Fable 5.1 192. Side by side on the same third-party tests, with price and context. The link in your address bar shares this exact comparison.
Claude Opus 5.5
197181–214
WeightsClosed
ReleasedSep 2026
Price in / out$4.0 / $20
Context1M
Core tests taken6 of 9
Claude Fable 5.1
192175–208
WeightsClosed
ReleasedSep 2026
Price in / out$10 / $50
Context1M
Core tests taken6 of 9
Claude Opus 5.5 leads Claude Fable 5.1 by 6 points, ahead on 4 of 5 shared core tests, and costs 2.5× less.
Test by testthird-party results
Claude Opus 5.5Claude Fable 5.1
Every result as a table
| Test | Claude Opus 5.5 | Claude Fable 5.1 |
|---|---|---|
| Reasoning & knowledge | ||
| LiveBench Data Analysis | 80.3% | 80.3% |
| LiveBench IF | 67.0% | 73.0% |
| LiveBench Language | 86.3% | 89.5% |
| LiveBench Reasoning | 92.2% | 91.7% |
| EBR-bench | 71.4% | 57.1% |
| SimpleQA Verified | 72.2% | 70.8% |
| Maths | ||
| FrontierMath (tiers 1-3) | 91.2% | 90.2% |
| AIME-style maths (OTIS mock) | 100.0% | 100.0% |
| LiveBench Mathematics | 97.1% | 97.0% |
| ProofBench v1.1 | 100.0% | 100.0% |
| Chess puzzles | 67.0% | 48.0% |
| FrontierMath (tier 4) | 95.0% | 87.8% |
| Coding | ||
| Terminal-Bench 4.0 | 65.1% | 58.1% |
| LiveBench Agentic Coding | 71.7% | 66.1% |
| LiveBench Coding | 89.3% | 86.4% |
| Code Migration | 66.6% | 54.6% |
| CyberBench v1.1 | 74.6% | 70.4% |
| IOI | 95.1% | 90.8% |
| ProgramBench | 18.5% | 7.0% |
| Vibe Code Bench 1-100 | 30.4% | 28.0% |
| Vibe Code Bench v1.1 | 90.3% | 90.3% |
| FrontierSWE | 62.3% | 56.3% |
| Agents | ||
| APEX-Agents | 73.5% | 68.6% |
| SRE Bench | 33.6% | 22.9% |
| Terminal-Bench-Science | 47.1% | 40.0% |
| DTBench | 98.9% | 97.6% |
| Furniture assembly | 83.3% | 70.0% |
| LMCA | 68.2% | 65.5% |
| Mystery game puzzles | 71.0% | 58.0% |
| Professional work | ||
| Finance Agent (v2) | 58.6% | 58.9% |
| EMB | 75.9% | 76.7% |
| Legal Research Bench | 50.5% | 55.3% |
| MedCode | 49.8% | 53.5% |
| MedScribe | 91.4% | 91.3% |
| Public Benefits Bench v1.1 | 70.6% | 74.9% |
| SAGE | 45.8% | 48.5% |
| Tax Agent Bench | 45.6% | 49.2% |
| Novel problems | ||
| ARC-AGI-2 | 93.3% | 90.0% |
| ARC-AGI-1 | 98.5% | 97.5% |
| MysteryMechanism | 49.5% | 47.8% |
Tests at least two of these models have taken. Bold rows are the core tests.
