Overview
- Deployment begins for paid ChatGPT tiers today, with an OpenAI API update due later this week and the prior GPT-5 kept in a legacy menu for three months.
- GPT-5.1 Instant targets everyday use with a warmer conversational tone, stronger instruction-following, and an adaptive reasoning feature that spends extra time on complex tasks.
- GPT-5.1 Thinking focuses on advanced reasoning by allocating its thinking time more effectively, replying faster to simple prompts, and producing clearer, less technical text.
- OpenAI will automatically route most user queries to either Instant or Thinking based on the task.
- Personalization expands to eight style presets, with limited tests letting some users fine-tune reply style, as the company cites a ChatGPT user base above 800 million.