Imagine an AI assistant that’s not just smart, but feels like a friend who truly gets you. That’s the promise of GPT-5.1, the latest evolution in the GPT series, designed to be more intelligent, engaging, and tailored to your needs. Today, we’re thrilled to introduce two groundbreaking models: GPT-5.1 Instant and GPT-5.1 Thinking, each pushing the boundaries of what conversational AI can achieve.
GPT-5.1 Instant: Your Go-To Companion
Meet the upgraded version of our most popular model, now warmer, sharper, and more attuned to your instructions. GPT-5.1 Instant isn’t just about answering questions—it’s about sparking conversations that feel natural and enjoyable. Early users have been delighted by its playful yet precise responses, proving that AI can be both fun and functional. But here’s where it gets exciting: for the first time, this model uses adaptive reasoning, deciding when to pause and think before answering complex queries. This results in more accurate, thorough answers without sacrificing speed, as evidenced by its stellar performance on math and coding challenges like AIME 2025 and Codeforces.
GPT-5.1 Thinking: Depth Meets Efficiency
Our advanced reasoning model has been reimagined to be faster on simple tasks and more persistent on intricate ones. It now dynamically adjusts its thinking time based on the question’s complexity, ensuring you get detailed answers for tough problems and quick responses for straightforward ones. Plus, we’ve stripped away the jargon, making its explanations clearer and more accessible—perfect for tackling work-related challenges or breaking down technical concepts. And this is the part most people miss: its default tone is now warmer and more empathetic, bridging the gap between intelligence and emotional connection.
Tailoring ChatGPT to Your Style
We know that everyone has unique preferences when it comes to conversation. That’s why we’ve introduced intuitive tone controls, allowing you to shape ChatGPT’s responses to match your mood or context. Whether you need a professional tone for work, a candid approach for brainstorming, or a quirky style for casual chats, we’ve got you covered. And for those who want even more control, we’re experimenting with granular adjustments—think tweaking conciseness, warmth, or emoji usage directly from settings. ChatGPT can even suggest tone updates mid-conversation based on your feedback, making customization seamless.
Controversial Question: Can AI Truly Understand Tone?
While GPT-5.1 makes significant strides in mimicking human-like tone, some argue that AI can never fully grasp the nuances of emotional context. What do you think? Can AI ever truly understand and adapt to tone in a way that feels indistinguishable from a human? Let us know in the comments!
Rollout Details and What’s Next
GPT-5.1 Instant and Thinking are rolling out today, starting with paid users (Pro, Plus, Go, Business) and gradually expanding to free and logged-out users. Enterprise and Edu plans get a seven-day early-access window. Legacy GPT-5 models will remain available for paid subscribers for three months, giving you time to compare and adapt. Both new models will also hit the API later this week, with adaptive reasoning included.
Looking ahead, we’re committed to making ChatGPT feel uniquely yours—smarter, more engaging, and endlessly adaptable. With GPT-5.1, we’re not just upgrading AI; we’re redefining what it means to converse with technology. Try it out, share your thoughts, and stay tuned for more innovations on the horizon!