Claude Sonnet 5.5 vs Grok 4.5
| Anthropic Claude Claude Sonnet 5.5 | xAI Grok 4.5 | |
|---|---|---|
| Vendor | Anthropic Claude | xAI |
| Context window | 1,000,000 | 500,000 |
| Max output | 128,000 | 2,000,000 |
| Reasoning | Yes | Yes |
| Tool calling | Yes | Yes |
| File input | Yes | Yes |
| Input | text, image, file | text, image |
| Output | text | text |
| Released | 2026-09-28 | 2026-07-08 |