Blog grok 4.1 fast

Grok 4.1 fast API
Nov 20, 2025
grok 4.1 fast
xAI

Grok 4.1 fast API

Grok 4.1 Fast is xAI’s production-focused large model, optimized for agentic tool-calling, long-context workflows, and low-latency inference. It’s a multimodal, two-variant family designed to run autonomous agents that search, execute code, call services, and reason over extremely large contexts (up to 2 million tokens).