OpenAI is a new breed of artificial intelligence that has advanced in the areas of perception, reasoning, and speech. GPT-5.1 I hereby officially introduce it. This model version is a major advancement in the GPT-5 series, becoming more natural in conversations with users, responding faster, and greatly improving its ability to understand deeper meanings.

CHATGPT 5.1 includes two new model types — GPT 5.1 Instant And GPT 5.1 Thinking It is designed to improve speed, content depth, and human-centered usability. 

GPT-5.1

GPT 5.1 Instant — a faster and more enjoyable experience

GPT 5.1 Instant is the most widely used model in ChatGPT, and is warmer and more natural than previous versions. The speed of speech response is increased and the ability to understand the user's intent is improved. 

Newly added ''Adaptive ReasoningThis feature allows the AI to decide on its own—based on the question—whether it should carefully think through the question before generating an answer, or respond immediately. Because of this, it can answer simple questions quickly, while taking more time to think for complex topics, providing more accurate and reliable responses. 

In additional tests, GPT 5.1 Instant achieved higher success rates than GPT-5.0 on math and coding tasks. 

GPT 5.1 Thinking — Deep thinking and conceptual clarity 

GPT 5.1 Thinking is a model developed for analyzing difficult topics. This version dynamically adjusts the thinking time based on each question. 

The most significant improvement of GPT 5.1 Thinking is “Clarity". Technical jargon is particularly suitable for use in academic studies, professional reports, and technical matters, as it increases the clarity of meaning based on the word. 

Additionally, the GPT 5.1 Thinking voice tone is softer and friendlier, providing a more family-like conversational experience in relevant contexts. 

Ability to change your voice and style to your liking 

OpenAI understands that it’s important for users to be able to “use AI in the way and with the voice they want.” In GPT 5.1, we’ve expanded the ability to customize the voice experience to suit the needs of the user. 

Users can choose from 6 preferred Tone Presets — 

Tone  Description 
Default  Natural and smooth solution 
Friendly  Talkative and happy 
Efficient  A precise, concise, and clear answer. 
Professional  Disciplined and with an office attitude 
Candid  Casual as it expresses an attitude 
Quirky  Delightful, artistic 

Additionally, you can customize emoji usage, font size (conciseness), and warmth. 

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GPT 5.1 Auto — Automatic model selection 

Newly added GPT 5.1 Auto The feature automatically selects GPT 5.1 Instant or GPT 5.1 Thinking based on each question. So users can get answers automatically and quickly without having to manually switch models. 

Developer Access 

For developers, GPT 5.1 is now available as an API. 

  • GPT 5.1 Instant → GPT 5.1-chat-latest 
  • GPT 5.1 Thinking → GPT 5.1 (adaptive reasoning included) 

This way, developers can create more sophisticated context-aware applications. 

 

Why is GPT 5.1 important? 

GPT 5.1 is Making AI more humane This is the most important step in the transformation. It has significantly improved reasoning, clarity, empathy, and personalization, making the conversation experience truly valuable for every user. 

Feature  GPT-5.0  GPT 5.1 Instant  GPT 5.1 Thinking 
Speed  Fast  Faster  Adaptive 
Reasoning  Moderate  High (Adaptive)  Very High 
Tone  Neutral  Warm & Conversational  Empathetic & Clear 
Ideal Use  General tasks  Everyday chat & writing  Deep analysis & explanation 

GPT-5.1 spends less time on easy tasks, and more time on hard tasks

What's next? 

OpenAI's three strategies are — 

  1. More meaningful Smarter Reasoning 
  2. For the speaking part Better Communication 
  3. You can use it as you like Greater Customization 

GPT 5.1 will become the default model across ChatGPT and the API, so every user will experience a new experience where they can interact with AI with a more human-like mindset.