AI Models
Explore available models and their capabilities
xAI
Released November 2025
Grok 4.1 Fast
Ultra-fast, 2M context, agentic tool calling
Reasoning
Tool Use
Vision
About this model
Grok 4.1 Fast is xAI's fastest variant in the Grok 4.1 series, engineered specifically for applications requiring rapid tool integration and function calling capabilities. With a 2-million-token context window, it accommodates lengthy documents and extended conversations. Users can enable or disable reasoning functionality through API parameters, balancing response speed against computational depth.
Context Window
2M
Input Cost
$0.20/M
Output Cost
$0.50/M
Input Types
Text, Image