Grok 4.1 Fast Reasoning vs Grok 4 Fast Reasoning

Grok 4.1 Fast Reasoning is xAI's most capable tool-calling model, engineered for production-grade agentic applications with a 2M token context window. Achieving state-of-the-art results on Berkeley Function Calling v4 and leading agentic search benchmarks like Research-Eval Reka (63.9) and FRAMES (87.6), it excels at multi-turn conversations, long-horizon planning, and autonomous task execution. Built through RL training in real-world simulated environments, Grok 4.1 Fast Reasoning delivers exceptional performance on complex enterprise scenarios like customer support and finance while cutting hallucination rates in half compared to its predecessor.

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.