Claude Fable 5.5 (Leaked Checkpoint) vs GLM-5-3 (Flagship)
A direct, empirical evaluation of Claude Fable 5.5 (Leaked Checkpoint) (Anthropic) against GLM-5-3 (Flagship) (Zhipu AI & THUDM).
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.
GLM-5-3 (Flagship)
Developed by Zhipu AI & THUDM · 744B parameters
Complex algorithmic reasoning, multi-step code synthesis, and long-horizon tool execution.
| Metric | Claude Fable 5.5 (Leaked Checkpoint) | GLM-5-3 (Flagship) |
|---|---|---|
| SWE-bench Verified | 84.2% | 54.8% |
| MMLU-Pro | 94.6% | 78.4% |
| MATH-500 | 98.4% | 93.6% |
| Context Window | 1,500,000 tokens | 256,000 tokens |
| Input Pricing (per 1M) | $3.50 | $0.55 |
| Output Pricing (per 1M) | $17.50 | $2.19 |