xAI Launches Grok 4.6, Matching GPT-5.6 Sol Max at the Same Price as Its Predecessor

xAI launched Grok 4.6 on August 12, 2026 — a 1.5-trillion-parameter model that, notably, reuses the same base architecture as Grok 4.5 rather than scaling up, delivering its performance gains entirely through improved supervised fine-tuning and reinforcement learning.

What Actually Improved

• Context window expanded to 500,000 tokens, with text and image inputs (text-only output)
• Reasoning effort now supports low, medium, high (default), and xhigh settings — giving developers explicit control over the speed-versus-depth tradeoff per request
• Scores 61 on the Artificial Analysis Intelligence Index — 4th place, behind Claude Opus 5, but matching GPT-5.6 Sol Max on the same benchmark

Pricing Held Steady, Which Is the Real Story

Pricing stayed at $2/$0.50/$6 per million tokens (input/cached input/output) below 200K prompt tokens, the same rate as Grok 4.5 — meaning xAI delivered a meaningfully more capable model without raising prices, at a moment when rivals are cutting prices aggressively too (OpenAI cut GPT-5.6 Luna pricing 80% the same month). The model is available via the xAI API, named gateway partners, and Amazon Bedrock.