gpt-5-pro vs Grok 4.5
| OpenAI gpt-5-pro | xAI Grok 4.5 | |
|---|---|---|
| Vendor | OpenAI | xAI |
| Context window | 400,000 | 500,000 |
| Max output | 272,000 | 2,000,000 |
| Reasoning | Yes | Yes |
| Tool calling | Yes | Yes |
| File input | Yes | Yes |
| Input | text, image | text, image |
| Output | text | text |
| Released | 2025-08-07 | 2026-07-07 |