OpenAI has begun a gradual rollout of GPT-5.1 into ChatGPT, which feels less like a patch and more like a polish: the model thinks more carefully when it needs to, uses a warmer, more human-sounding voice, and offers users clearer control of the tone and behaviour of their chat partner.
The reasoning is smarter — with no delay
One of the main feature changes is expanded access to an “adaptive reasoning” capability — which simply means ChatGPT has learned more in terms of determining when a question requires an instant response (like “What is the weather like today?) and determining when it needs to try to reason, through an example out loud, or through mathematically complex scenarios.
A softer, more human voice
Users have indicated that GPT-5.1 “feels warmer.” OpenAI has made adjustments to the conversational pacing, phrasing, and polite default for responses to feel less robotic and more empathetic. The update also tightens privacy-sensitive actions and clarifies expressions of uncertainty, reducing the blunt, overconfident responses users have complained about in previous iterations.
Personalities and customisation — choose a voice for the job
GPT-5.1 also introduces simpler customising controls and a set of personality presets (think: Default, Professional, Friendly, Candid, Quirky, Efficient, Nerdy and Cynical), so you can influence the assistant’s style, without rewriting your prompt.
Faster, more reliable tasks of everyday use
For basic use cases — summarise emails, draft communications, plan a trip, generate pieces of code — Insant is configured to be fast and accurate. For cases that are more reliable, the Thinking model is called in, where waiting a little longer is acceptable in exchange for depth and clarity. The early testing and guides also make some practical prompt examples available to enable users to gauge the strengths of the new models.
Rollout, limits and who gets it first
OpenAI is rolling GPT-5.1 out incrementally: paid subscribers get it first with higher limits on use…then it opens up for broader access. There are usage limits that apply temporarily for free tier use — paid subscriptions get more use allowances — a reminder that the cutting-edge models usually start behind a paywall as part of staged access. OpenAI’s release notes and help centre explain the new limits and how the Instant/Thinking routing version works.
Safety and quality updates under the hood
In addition to user-facing features, GPT-5.1 also has safety and alignment updates built in — better refusal behaviour on harmful prompts and clearer handling of uncertainty are two of the improvements, along with updates intended to reduce hallucinations on tricky factual questions. OpenAI has indicated that those are iterative improvements to the GPT-5 family rather than some brand new frontier-defining model.
