Claude Fable 5.5 (Leaked Checkpoint) vs Claude Opus 5.5 (Canary Checkpoint)
A direct, empirical evaluation of Claude Fable 5.5 (Leaked Checkpoint) (Anthropic) against Claude Opus 5.5 (Canary Checkpoint) (Anthropic).
Claude Fable 5.5 (Leaked Checkpoint)
Developed by Anthropic · Proprietary Frontier Dynamic Reasoner parameters
Terminal-Bench 4.0 autonomous shell execution (78.5% target), recursive self-critique, and 1.5M-token repository refactoring.
Claude Opus 5.5 (Canary Checkpoint)
Developed by Anthropic · Frontier Mixture-of-Experts Architecture parameters
Autonomous repository issue resolution (81.4% SWE-bench Verified), native 3D glTF/OBJ mesh synthesis, and sub-300ms time-to-first-token.
| Metric | Claude Fable 5.5 (Leaked Checkpoint) | Claude Opus 5.5 (Canary Checkpoint) |
|---|---|---|
| SWE-bench Verified | 84.2% | 81.4% |
| MMLU-Pro | 94.6% | 94.2% |
| MATH-500 | 98.4% | 97.9% |
| Context Window | 1,500,000 tokens | 1,000,000 tokens |
| Input Pricing (per 1M) | $3.50 | $5.00 |
| Output Pricing (per 1M) | $17.50 | $25.00 |