OpenAI has officially rolled out GPT-5.1, the newest version of its language model, designed to make ChatGPT feel more responsive, accurate and natural during conversations. The update comes in two forms, GPT-5.1 Instant and GPT-5.1 Thinking, each aimed at handling user questions in a more efficient way.
What’s new with the model versions
GPT-5.1 Instant focuses on delivering smoother, more precise replies while doing a better job of following instructions. On the other hand, GPT-5.1 Thinking is built for consistency, especially during longer chats or complicated tasks, and performs quicker on simpler prompts. ChatGPT will automatically switch between these models depending on what kind of answer the user needs.
Both variants will roll out to users over the next week. Older GPT-5 models will still be available under the legacy section for about three months before OpenAI retires them.
More ways to customise ChatGPT
The update also brings expanded personality presets, giving users more control over how ChatGPT sounds. You can now choose from eight tones: Default, Professional, Friendly, Candid, Quirky, Efficient, Nerdy and Cynical. These styles help users tune ChatGPT’s vibe depending on the task, whether it’s writing an email, brainstorming ideas or having a casual chat.
OpenAI is also testing a deeper customisation tool that lets users fine-tune communication style directly from settings. This feature will reach more users gradually.
In a Substack post, OpenAI Applications CEO Fidji Simo said that with ChatGPT crossing 800 million users, offering different conversational styles has become crucial. One single tone simply doesn’t fit everyone anymore.
User reactions and rising competition
The earlier GPT-5 update from August received mixed reviews, with many users saying the improvements didn’t feel significant. After that feedback, OpenAI quickly brought back GPT-4o as an optional model.
Meanwhile, OpenAI’s close partner Microsoft has also been testing other models from Anthropic. These are being used in several tools, including Copilot Researcher, GitHub Copilot, Copilot Studio and Microsoft’s upcoming Office Agent for automating tasks in Word and PowerPoint.
Part of a bigger ecosystem shift
The GPT-5.1 launch comes shortly after OpenAI introduced ChatGPT Atlas, a new AI-powered web browser with an “agent mode” that can perform tasks directly inside the browser. For now, it’s limited to ChatGPT Plus and Pro users.
With GPT-5.1 rolling out, OpenAI says it’s taking another step toward making ChatGPT more flexible, more helpful and more aligned with different user needs across its ecosystem.
