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
Context
2M
Released
Nov 19, 2025
Token volume and request traffic to this model over time.
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
Grok 4.1 Fast has a 2,000,000 token context window.
Grok 4.1 Fast accepts text, images and files such as PDFs as input and returns text.
Grok 4.6, Grok 4.5, Grok Build 0.1 and 3 more are other text models from SpaceXAI.
Grok 4.1 Fast was released on November 19, 2025.