Claude Opus 5 vs Grok Build 0.1
| Anthropic Claude Claude Opus 5 | xAI Grok Build 0.1 | |
|---|---|---|
| Vendor | Anthropic Claude | xAI |
| Context window | 1,000,000 | 256,000 |
| Max output | 128,000 | — |
| Reasoning | Yes | Yes |
| Tool calling | Yes | Yes |
| File input | Yes | Yes |
| Input | text, image, file | text, image |
| Output | text | text |
| Released | 2026-07-24 | 2026-05-30 |