OpenAI makes GPT-5.6 Sol more reliable and gives free users unlimited GPT-5.6 Luna — here's what the new tiering actually buys you

On August 6, 2026, OpenAI rolled out a major ChatGPT update: GPT-5.6 Sol gets a reliability upgrade for Plus and Pro subscribers, while free users gain unlimited text conversations with GPT-5.6 Luna. If you're still paying for ChatGPT without knowing what changed, here's the real cost-benefit math.