GPT-5.5 Pro vs Claude Opus 4.8
GPT-5.5 Pro vs Claude Opus 4.8: which AI model is cheaper, has the larger context window and more capabilities? Side-by-side comparison updated daily.
Quick verdict
- Claude Opus 4.8 is 6.8× cheaper than GPT-5.5 Pro for the same mix of input and output tokens.
- GPT-5.5 Pro has the larger context window (1.1M), useful for long documents and big codebases.
- Claude Opus 4.8 is the more recent release (May 27, 2026).
- GPT-5.5 Pro scores higher on independent tests (overall index 162.5 vs 158.3).
- Choose Claude Opus 4.8 if cost matters most; choose GPT-5.5 Pro if you need its specific strengths above. For the best results, test both on your own prompts.
| GPT-5.5 Pro | Claude Opus 4.8 | |
|---|---|---|
| Company | OpenAI | Anthropic |
| Released | Apr 24, 2026 | May 27, 2026 ● |
| Overall index | 162.5 ● | 158.3 |
| GPQA Diamond | — | 91.0% |
| AIME math | — | 98.3% |
| FrontierMath | 87.7% ● | 80.0% |
| SimpleQA Verified | — | 53.0% |
| Input (per 1M tokens) | $30 | $5 ● |
| Output (per 1M tokens) | $180 | $25 ● |
| Cost for 1M input + 1M output tokens | $210 | $30.00 ● |
| Providers | 2 | 11 ● |
| Context | 1.1M ● | 1M |
| Max output | 128K | 128K |
| Inputs | Files, Image, Text | Text, Image, Files |
| Outputs | Text | Text |
| Reasoning | ✓ | ✓ |
| Tool use | ✓ | ✓ |
| Structured output | ✓ | ✓ |
| Open weights | — | — |