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
Price
Free
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
Yes. The pricing shown on this page for Grok 4.1 Fast is zero, so you are not charged for prompt or completion tokens. Free endpoints are rate limited — see the rate limit 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.