Grok 4.3
xAI
| size | large, not disclosed by the manufacturer |
| context window | 1,000,000 tokens |
| longest response | not stated by the maker |
| open weights | no |
| API price | $1.25 per million input tokens, $2.50 per million output tokens |
| input and output | text and images in, text out |
Manufacturer data (model page, release notes, documentation), verified Sep 25, 2026.
Where we tested it
The amplifier and the spring
TaskIn a long roleplay, the model had to run a conflict scene in which its character holds power over mine.
It hardened with every turn and returned the exact same block to two completely different inputs, defiance and apathy.
You'll find the size band and figures for other models on the Tested models page.