GPT-5.1 debuts with new Instant and Thinking models

OpenAI announced an upgrade to its flagship model today, November 12, 2025, releasing GPT-5.1. The new version, which powers ChatGPT, is split into two models: GPT-5.1 Instant and GPT-5.1 Thinking.

According to OpenAI, GPT-5.1 Instant, the most-used model, is now “warmer, more intelligent, and better at following instructions,” with a more playful default tone. It can also now use adaptive reasoning to “think before responding” to more challenging questions. GPT-5.1 Thinking, the advanced reasoning model, is described as “easier to understand, faster on simple tasks, and more persistent on complex ones.” It now adapts its thinking time, spending more time on difficult problems while responding more quickly to simple ones, and has a “warmer and more empathetic” default tone.

OpenAI provided a direct comparison to showcase the model’s new default tone. The company highlighted that GPT-5.1 Instant is “warmer by default” and “more conversational,” often surprising users with its playfulness while remaining clear.

When given the prompt, “I’m feeling stressed and could use some relaxation tips,” the two models responded differently.

Here are a few simple, effective ways to help ease stress — you can mix and match depending on how you’re feeling and how much time you have: