Particle.news
Download on the App Store

OpenAI Begins Rolling Out GPT-5.1 With Instant and Thinking Models

The update emphasizes a more natural chat experience through adjustable personalities with adaptive reasoning.

Overview

  • GPT-5.1 is available now to Pro, Plus, Go and Business subscribers in a staged release, with Enterprise and Education granted a seven‑day early access window and free users to follow in the coming days.
  • The release comes in two variants: Instant uses adaptive thinking to spend more time on complex prompts, while Thinking is positioned as OpenAI’s most advanced reasoning model.
  • OpenAI adds expanded personality settings that make responses friendlier or more concise, including options such as Friendly, Efficient, Professional and a quirky style, with the assistant able to suggest tone adjustments.
  • Legacy GPT-5 Instant and Thinking remain for paying users for roughly three months, while OpenAI updates Pro to 5.1 Pro and publishes a System Card addendum detailing safety and evaluation changes.
  • OpenAI links the tone overhaul to user feedback and internal findings about severe mental‑health symptoms in a subset of users, and it says a December release is planned to introduce an erotic feature for verified adults.