gpt-5-pro vs Claude Opus 5.5
| OpenAI gpt-5-pro | Anthropic Claude Claude Opus 5.5 | |
|---|---|---|
| Vendor | OpenAI | Anthropic Claude |
| Context window | 400,000 | 1,000,000 |
| Max output | 272,000 | 128,000 |
| Reasoning | Yes | Yes |
| Tool calling | Yes | Yes |
| File input | Yes | Yes |
| Input | text, image | text, image, file |
| Output | text | text |
| Released | 2025-08-07 | 2026-09-22 |