xAI launches Grok 4.6, matching GPT-5.6 Sol on benchmarks

xAI released Grok 4.6 on August 12, a 1.5-trillion-parameter model built on the same foundation as Grok 4.5 but tuned through improved supervised fine-tuning and reinforcement learning for long-running agent tasks, coding and knowledge work, with a 500,000-token context window. The model scored 61 on the Artificial Analysis Intelligence Index, matching OpenAI's GPT-5.6 Sol and just behind Anthropic's Claude Fable 5, and shipped the same day in the Cursor code editor and xAI's own Grok Build tool alongside API access priced at $2/$6 per million input/output tokens.