Grok 4.6 Ships at the Same Price as 4.5, Until Your Prompt Hits 200K Tokens and the Whole Request Doubles
xAI released Grok 4.6 on August 12 at Grok 4.5's identical $2/$6 per million headline rate with the same 500K context window. But xAI's pricing docs contain a rule the launch post never mentions: once a prompt reaches 200,000 tokens, every token in the request, including cached input and output, bills at $4/$12. That means the advertised rate covers only the first 40% of the advertised window, and cached input quietly rose 67% from $0.30 to $0.50 per million, hitting exactly the long-running agent loops xAI says this model is built for.


