Open AI announces ChatGPT 5.1

On Wednesday OpenAI announced GPT 5.1, what OpenAI is calling an "upgrade" to GPT 5 which was announced back in August (2025), and OpenAI claims the new model, GPT 5.1 "makes ChatGPT smarter and more enjoyable to talk to".

The new models are GPT-5.1 Instant and GPT-5.1 thinking. Alongside the release of the new models comes with new conversation tones. The list of tones now include Default, Professional, Friendly, Candid, Quirky, Efficient, Nerdy, and Cynical.

The release of GPT 5.1 comes just weeks after OpenAI announced its AI-powered web browser, ChatGPT Atlas.