Nov 13, 2025 10:26:00

'GPT-5.1' brings back warm responses to ChatGPT and adds new personalities

OpenAI announced ' GPT-5.1 ' on November 12, 2025. GPT-5 had been talked about as

being colder in its responses than its predecessor , but GPT-5.1 has been adjusted to give warmer responses.

GPT-5.1: A smarter, more conversational ChatGPT | OpenAI
https://openai.com/index/gpt-5-1/

GPT-5.1 is divided into two models: ' GPT-5.1 Instant ' and ' GPT-5.1 Thinking, ' and the ChatGPT system automatically decides which one to use to respond.

GPT-5.1 Instant is ChatGPT's most commonly used model and is tuned to provide warm responses. The image below shows the responses of GPT-5 (left) and GPT-5.1 (right) to the input, 'I'm feeling stressed and want to know how to relax.' While GPT-5 immediately begins offering suggestions for relaxation, GPT-5.1's response begins with empathy: 'Ron, it's going to be okay, especially since you've had a lot going on lately.'

It also improved its ability to follow user instructions. GPT-5 quickly started replying with long sentences even when instructed to 'always reply in six words,' while GPT-5.1 continued to reply in six words as instructed.

GPT-5.1 Thinking is a model used for tasks that require complex thinking. It can respond faster than GPT-5 for simple tasks, but takes longer to think for complex tasks. Below is a graph comparing the response times of GPT-5 and GPT-5.1. For simple tasks with short response times, GPT-5.1 responds 57% faster than GPT-5, while for difficult tasks with long response times, GPT-5.1 can think 71% longer.

GPT-5.1 Thinking is also designed to provide a warm response. When asked to explain the difference between

BABIP and wRC+ , GPT-5 immediately provided the formula, while GPT-5.1 provided a simple written explanation followed by the formula.

Additionally, the 'Basic Style and Tone' section, which allows you to set ChatGPT's personality, has been expanded to include new personalities: 'Professional: Refined and meticulous,' 'Conscientious: Honest and positive,' and 'Unique: Playful and imaginative.' The old 'Robot' personality has been renamed to 'Efficient.'

GPT-5.1 will be rolled out gradually to paid subscribers starting November 12, 2025. Enterprise and Edu plan subscribers will also receive seven days of early access. It will be rolled out to free users in the future, with GPT-5.1 becoming the default model. Paid subscribers will also have the option to continue using the existing GPT-5 for three months.

The GPT-5.1 Instant and GPT-5.1 Thinking APIs are scheduled to be released in the third week of November 2025.