GPT-5.1 Update Boosts ChatGPT's Brainpower And Personality Range — Check Details

OpenAI has unveiled GPT-5.1, an upgrade to its flagship GPT-5 model launched in August, describing it as an improvement that makes ChatGPT “smarter and more enjoyable to talk to.”

The update introduces two versions: GPT-5.1 Instant and GPT-5.1 Thinking. According to OpenAI, the Instant model is “warmer, more intelligent, and better at following instructions,” while the Thinking model is “easier to understand, faster for simple tasks, and more persistent on complex ones.”

ChatGPT will automatically route most queries to the model best suited for the task. The rollout for users begins this week, with the older GPT-5 versions remaining accessible for three months via the legacy models dropdown before being phased out.

OpenAI is also expanding its personality presets for conversational tone. The list now includes Default, Professional, Friendly, Candid, Quirky, Efficient, Nerdy, and Cynical, as noted in the company’s blog post. Additionally, it plans to test a new feature that allows users to fine-tune ChatGPT’s style directly from settings, with early access starting this week.

“With more than 800 million people using ChatGPT, we’re well past the point of one-size-fits-all,” wrote Fidji Simo, OpenAI’s CEO of Applications, in a Substack post on Wednesday.

The launch of GPT-5 in August had generated high expectations, but many users were underwhelmed by the incremental improvements and criticized OpenAI’s decision to make it the default model. The backlash prompted the company to restore GPT-4o as an optional model just a day after GPT-5’s debut.

Meanwhile, Microsoft, OpenAI’s strategic partner, has been exploring alternatives from Anthropic, whose models now help power Copilot Researcher, GitHub Copilot, Copilot Studio, and Microsoft’s new Office Agent, capable of generating Word and PowerPoint documents via the Copilot interface.

The GPT-5.1 announcement follows shortly after the launch of ChatGPT Atlas, OpenAI’s AI-powered web browser. Currently available to ChatGPT Plus and Pro users, it features an “agent mode” that functions similarly to OpenAI’s Operator tool, allowing the AI to take actions within the browser on behalf of users.