Grok 4.1 Fast is xAI's best agentic tool calling model that shines in real-world use cases like customer support and deep research. 2M context window.
Reasoning can be enabled/disabled using the reasoning enabled parameter in the API. Learn more in our docs(opens in new tab)
Modalities
In / Out Price
$0.20 / $0.50per 1M
Context
2M
Weekly Rank
#11on OpenRouter
Going away May 15, 2026