Claude Opus 5.5 vs GPT-6 Astra
A direct, empirical evaluation of Claude Opus 5.5 (Anthropic) against GPT-6 Astra (OpenAI).
Claude Opus 5.5
Developed by Anthropic · Proprietary Frontier Reasoner parameters
Autonomous enterprise codebase migrations, GitHub Copilot multi-file edits, SWE-bench Pro issue resolution (89.9%), and CodeRabbit automated reviews.
GPT-6 Astra
Developed by OpenAI · Proprietary Frontier parameters
Complex multi-step engineering, formal math proofs, autonomous computer/browser navigation, and CAD synthesis.
| Metric | Claude Opus 5.5 | GPT-6 Astra |
|---|---|---|
| SWE-bench Verified | 89.9% | 79.4% |
| MMLU-Pro | 92.4% | 91.2% |
| MATH-500 | 97.2% | 98.6% |
| Context Window | 500,000 tokens | 1,050,000 tokens |
| Input Pricing (per 1M) | $4.00 | $10.00 |
| Output Pricing (per 1M) | $20.00 | $50.00 |