OpenAI Deploys GPT-5.1 Update Featuring Warmer Tone and Adaptive Reasoning

OpenAI today, November 12, 2025, announced a major upgrade to its flagship model, introducing GPT-5.1. Instead of focusing purely on raw performance, the company has concentrated on making interactions with ChatGPT feel more natural, intuitive, and "warm." The update has already begun rolling out to paid subscribers.

​The release includes two new model versions: GPT-5.1 Instant, which is now more conversational and playful, and GPT-5.1 Thinking, the advanced model for complex reasoning.

​According to the announcement, the primary change in GPT-5.1 Instant is its communication style. The model is "warmer" by default, has improved its ability to follow instructions, and, according to early testers, often surprises users with its playfulness while remaining clear and useful. Side-by-side comparisons in OpenAI's blog post show the new model avoiding robotic responses in favor of more empathetic and natural phrasing.

​GPT-5.1 Thinking, in turn, has become more efficient. It now handles simple tasks more quickly while being more persistent on complex ones. The model has learned to dynamically allocate "thinking time," which in practice means less waiting for simple requests. Furthermore, its responses are now clearer, with less technical jargon.

​A key new capability for GPT-5.1 Instant is its use of "adaptive reasoning." The model can now decide for itself when it needs to "think" before responding to more challenging questions, leading to significant improvements in math and coding accuracy.

​Alongside the models, OpenAI is simplifying the process of customizing ChatGPT's tone. Users can now choose from refined styles like "Professional," "Candid," and "Quirky" to instantly tailor the AI's responses to their needs.