GPT-5.1: OpenAI makes ChatGPT warmer and smarter

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OpenAI has released a new update for ChatGPT: GPT-5.1. Three months after the launch of GPT-5, the next generation has arrived, which the company says is "warmer, smarter, and better at following instructions." With this new model, OpenAI aims to make communication more natural and interaction with ChatGPT more precise and personalized. GPT-5.1 brings improvements in several areas—from tone of voice and comprehension to persistence with complex tasks.

With GPT-5.1, OpenAI is focusing on refinement rather than revolution. The update improves not only how ChatGPT speaks, but also how it thinks. GPT-5.1 sounds more natural, less technical, and is designed to perform tasks more reliably. OpenAI is also introducing new controls that allow users to adjust the model's tone. The goal is for ChatGPT to better respond to the desired communication style and for its responses to sound more human.

Improvements to Instant and Thinking

As with GPT-5, OpenAI offers two versions of the model: GPT-5.1 Instant and GPT-5.1 Thinking. Both have received a significant upgrade, but with different focuses.

GPT-5.1 Instant is the most widely used model. It has been redesigned to provide friendlier, smarter, and more precise responses. OpenAI emphasizes that instant responses now sound more natural and less like standardized data output. GPT-5.1 Instant understands instructions better—even short commands like "Reply with six words" are executed correctly. This capability was previously a weakness of earlier versions of ChatGPT.

In contrast, GPT-5.1 Thinking focuses on logical and analytical reasoning. According to OpenAI, it is faster at simple tasks but demonstrates greater persistence and precision with complex queries. The model is designed to better structure tasks requiring more thought while maintaining a new, more engaging tone. This makes even the deeper levels of reasoning seem less mechanical and more comprehensible.

Another feature remains: Auto-Routing. This technology automatically decides whether GPT-5.1 Instant or GPT-5.1 Thinking is better suited for a task. Alternatively, the model can also be selected manually for each input. This allows switching between faster or more thorough processing depending on the situation.

More control over tone and style

A key new feature of GPT-5.1 concerns tone of voice. OpenAI has introduced new options to more precisely control the model's personality. ChatGPT can now adopt different styles that adapt to various communication situations. The new personality options include "Standard," "Friendly," "Efficient," "Professional," "Open," and "Quirky.".

This allows for more precise customization of the model's responses – depending on whether it's a formal email, a technical document, or a casual conversation. OpenAI speaks of "more intuitive and effective control options" designed to help better achieve the desired tone in responses.

Better understanding of instructions

Another key focus is on instruction following. GPT-5.1 responds more precisely to specific instructions and can better distinguish between different writing styles, formats, and word lengths. OpenAI demonstrates in its own examples that the model now fulfills specific requirements much more reliably.

Furthermore, the overall style of writing has been revised. GPT-5.1 uses a more natural, dialogue-oriented style. Responses sound less formulaic and more like human communication. OpenAI refers to this approach as the new standard for ChatGPT.

Availability and transition phase

GPT-5.1 is now being rolled out to paying customers, including users of the Pro, Plus, Go, and Business plans. OpenAI announces that the rollout will continue over the next few days until all paying customers have access. Afterward, the update will also be available to free and logged-out ChatGPT users.

The existing GPT-5 will remain available for at least another three months. This is OpenAI's response to criticism from the summer when older models were discontinued too quickly after the introduction of GPT-5. This gives users more time to prepare for the switch to the new system.

Apple also plays a role in this context. The company has announced that ChatGPT via Siri, using Apple Intelligence, will be based on GPT-5 starting with iOS 26. It is expected that the integration will be upgraded to GPT-5.1 in a future software update.

ChatGPT: More naturalness, precision and control with GPT-5.1

GPT-5.1 isn't a complete reboot, but rather a targeted enhancement. The update ensures that ChatGPT sounds more natural, understands instructions better, and completes tasks more efficiently. At the same time, it provides more control over tone of voice and style, allowing the AI to adapt more flexibly to different work environments.

With the introduction of GPT-5.1, OpenAI strengthens its position as a leading provider in the field of generative AI. The model demonstrates how technological precision and human expression are increasingly converging. GPT-5.1 thus represents a further step towards communication that is not only intelligent but also authentic. (Image: Shutterstock / Diego Thomazini)