GPT-6 Sol vs grok-4-fast-reasoning
| OpenAI GPT-6 Sol | xAI grok-4-fast-reasoning | |
|---|---|---|
| Vendor | OpenAI | xAI |
| Context window | 1,050,000 | 2,097,152 |
| Max output | 128,000 | 30,000 |
| Reasoning | Yes | Yes |
| Tool calling | Yes | Yes |
| File input | Yes | Yes |
| Input | text, image | text, image |
| Output | text | text |
| Released | 2026-09-22 | 2025-08-27 |