Grok 4 Fast Reasoning
grok-4-fast-reasoning
by x-ai|Created Sep 20, 2025
State-of-the-art reasoning model optimized for cost-efficient, high-quality chain-of-thought. Trained end-to-end with tool use and agentic search, it matches top-tier benchmarks like AIME, HMMT, and GPQA at 40% lower token use versus Grok 4. Features a huge 2M token context and native web/X browsing. Ideal for agentic workflows, research, code, logic, and complex multi-step tasks. Offers up to 98% cheaper reasoning versus previous models.