Grok 4.1 Fast
xAI · 2025-11-19
Grok 4.1 Fast is xAI's low-latency variant of Grok 4.1, released in November 2025 alongside the Agent Tools API for developers. It is optimized for speed and cost-efficiency in agentic workflows, offering fast response times while retaining strong instruction-following and tool-calling capabilities. The model is intended for high-throughput applications where rapid turnaround is prioritized over maximum reasoning depth. The xAI API serves it as two model IDs, `grok-4-1-fast-reasoning` and `grok-4-1-fast-non-reasoning`.