OpenAI rolls out ChatGPT update with GPT 5.1 models — what’s new for the users

OpenAI on Thursday, 13 November, rolled out its new GPT 5.1 models for ChatGPT, introducing two upgraded versions for users: GPT-5.1 Instant and GPT-5.1 Thinking. In its blog post, the Sam Altman-led company said these versions are “not only smarter but also enjoyable to talk to”.

According to OpenAI, these models are designed to make it easier for a user to personalise their ChatGPT experience by adjusting the AI’s tone and style. Users can now set preferences for how they want the chatbot to sound, enabling ChatGPT to better match their desired tone in conversations.

What’s new about GPT‑5.1 Instant?

OpenAI described GPT‑5.1 Instant as “warmer” by default and more conversational. “Based on early testing, it often surprises people with its playfulness while remaining clear and useful,” the company wrote in its blog post.

The company explained that since GPT‑5.1 Instant is the most widely used model, it has been built to be more responsive to instructions, hence providing a better conversational flow. OpenAI also added that the model is capable of deciding when it should “think before responding” to more challenging questions. The stated goal is simple: Give accurate answers while still responding quickly.

What’s new about GPT‑5.1 Thinking?

OpenAI said GPT-5.1 Thinking, on the other hand, is designed for doing deeper reasoning tasks. It’s trained to manage its thinking time more precisely to the question, spending more time on complex problems while responding quickly to simpler prompts.

This model also provides clearer responses, with less jargon and fewer undefined terms, than the previous versions, making it ideal for fulfilling complex tasks at work and explaining technical concepts.

When will these models be available for users?

OpenAI announced that GPT‑5.1 Instant and Thinking will begin rolling out today, 13 November, starting with paid (Pro, Plus, Go, Business) users. Free and logged-out users will get access over the next few days. Whereas, Enterprise and Edu plan customers will get a seven-day early-access toggle before the update becomes the sole default model.

OpenAI said the rollout is gradual, so availability may vary by user. The company also confirmed that the GPT-5 Pro version will soon be upgraded to GPT-5.1 Pro.

Options to customise ChatGPT’s tone and style

Alongside these model improvements, ChatGPT is also offering users options to customise its tone and style. The eight styles available are:

— Friendly (formerly Listener)

— Efficient (formerly Robot)

— Cynical (formerly Cynic)

— Nerdy (formerly Nerd)

Beyond these presets, OpenAI explained that it is experimenting with new personalisation options for users who want more precise control. These settings will allow users to fine-tune the chatbot’s characteristics, including how concise, warm, or scannable its responses are, as well as how often it uses emojis.

OpenAI said these fine-tuning features will be introduced as an experiment to a limited group of users later this week, while the updated tone and style presets begin rolling out on Thursday.