Grok 4.1 Fast
by xAI
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)
Capabilities
Pricing
Input Tokens
Per 1M tokens
Free
Output Tokens
Per 1M tokens
Free
Image Processing
Per 1M tokens
$0.00/1M tokens
Supported Modalities
Input
text
image
Output
text
Specifications
- Context Length
- 2.0M tokens
- Provider
- xAI
- Released
- Nov 19, 2025
- Model ID
- x-ai/grok-4.1-fast
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