GPT-5.1 Instant and Thinking

Smarter, more conversational ChatGPT with new personalities GPT-5.1 Instant and Thinking are trained using the same stack as OpenAI's reasoning models, so they score higher on factuality and complex problem-solving than GPT-5, while also introducing a more natural, conversational tone. We think many people will find that GPT-5.1 does a better job of bringing IQ and EQ together, but one default clearly can’t meet everyone’s needs.