xAI: Grok 4.1 Fast
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](https://openrouter.ai/docs/use-cases/reasoning-tokens#controlling-reasoning-tokens)
Undisclosed
Parameters
2.0M tokens
Context Window
Proprietary
License
Nov 19, 2025
Released
💰 Pricing
Input
$0.20
per 1M tokens
Output
$0.50
per 1M tokens
API Available
This model is accessible via API for integration into your applications.
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