OpenAI is releasing GPT-5.1 today, an update to the flagship model released in August. OpenAI calls it an “upgrade” to GPT-5 that “makes ChatGPT smarter and more fun to talk to.”
The new models include GPT-5.1 Instant and GPT-5.1 Thinking. According to the OpenAI release, the former is “hotter, more intelligent, and better at following your instructions” than its predecessor, and the latter is “now easier to understand and faster on simple tasks, and more stable on complex tasks.” In most cases, queries will be automatically matched to models that may be best able to answer them. The two new models will begin becoming available to ChatGPT users this week, and the older GPT-5 models will remain available in ChatGPT’s legacy models dropdown menu for three months before disappearing.
As part of the update, OpenAI also said it will expand its personality presets for models’ conversational tone. According to the company’s blog post, the total list of options now includes Default, Professional, Friendly, Candid, Quirky, Efficient, Nerdy, and Cynical. OpenAI also said in a release that it would also begin “experimenting with new ways to fine-tune the style of ChatGPT directly from Settings,” which some users will begin accessing this week.
“With over 800 million people using ChatGPT, we’re well past the point of one-size-fits-all,” the company’s Applications CEO Fidzi Simo wrote in a Wednesday Substack post.
While OpenAI CEO Sam Altman publicized the announcement of GPT-5 in August, the release failed the hype test. Many ChatGPT users were not impressed, particularly by the incremental improvements, and expressed disappointment at OpenAI’s choice to make it the default model for ChatGPT. There was so much pressure that OpenAI decided it would bring back GPT-4o as an option a day after the launch of GPT-5.
OpenAI’s strategic AI partner Microsoft is also increasingly considering rival models to Anthropic after failing to adequately raise the GPT-5 standard. Anthropic’s models now support Power CoPilot Researcher, GitHub CoPilot, CoPilot Studio, and a new Office agent that’s able to create Word and PowerPoint documents from Microsoft’s own CoPilot chat interface.
The announcement of GPT-5.1 comes just weeks after OpenAI launched its AI-powered web browser, ChatGPT Atlas. It has an “Agent Mode” that is currently only available to ChatGPT Plus and Pro users, and it acts like the company’s operator tool to take actions in the browser on behalf of users.