ChatGPT-maker OpenAI releases GPT-5.1, fixing GPT-5’s tone problem with personality presets and warmer tone

OpenAI is releasing GPT-5.1, overhauling its flagship model with two smarter variants—GPT-5.1 Instant and GPT-5.1 Thinking—that promise warmer conversations and sharper instruction-following. The refresh arrives three months after GPT-5’s rocky August launch, when users complained the model felt cold and often fumbled tasks that older versions handled better.

GPT-5.1 Instant powers most ChatGPT interactions with snappier, more natural dialogue, while GPT-5.1 Thinking tackles complex problems with extended reasoning. Both models promises to gauge question difficulty on the fly, devoting extra processing to tough queries while firing off quick answers to simple ones.