OpenAI launches GPT-5.1: a more conversational ChatGPT | Keryc
OpenAI introduces GPT-5.1, an update to the GPT-5 series that aims to make ChatGPT smarter and, above all, nicer to talk to. The rollout starts today and will be gradual, beginning with paid users. It combines improvements in reasoning with simpler controls to tweak the tone of responses.
What's in GPT-5.1
The 5.1 release updates two main flavors: GPT-5.1 Instant and GPT-5.1 Thinking. Instant is the most used model: it now replies with a warmer, more conversational tone, follows instructions more reliably, and uses adaptive reasoning when the question deserves it. Thinking is the one specialized in advanced reasoning: it's now clearer, less overly technical, and better at deciding how much time to spend on each problem.
So what does that mean in practice? Instant will give you quick, more natural answers for everyday tasks: writing emails, summarizing texts, or helping you brainstorm ideas. Thinking will dedicate more "mental time" to complex problems, so you'll see more complete answers in math, programming, or deep analysis.
OpenAI points to concrete improvements on math and coding evaluations like AIME 2025 and Codeforces, which suggests better accuracy on difficult problems without sacrificing speed for simple queries.
Tone personalization: more control without the hassle
One of the core ideas is that the same AI can sound different depending on context. To support that, they expanded style options: Default, Friendly, Efficient, and now they add Professional, Candid, and Quirky, while keeping Cynical and Nerdy. Easy, right?
Beyond presets, they're testing fine-grained controls to adjust how concise, warm, or scannable you want the AI to be, and even how often it uses emojis. ChatGPT can suggest style changes when it detects you asking for them in the conversation, and adjustments apply to all chats instantly.
User experience and what to watch for
GPT-5.1 Auto will keep choosing the most appropriate model for you in most cases, so you don't need to pick anything if you don't want to.
Answers should feel more natural and with less technical jargon in the Thinking model.
If you like to compare, the GPT-5 Instant and Thinking versions remain available in the legacy models menu for three months so you can evaluate.
Think of it like trying a new version of an app: some things change immediately, others arrive gradually so the experience doesn't break.
Availability and API
The rollout begins today for paid subscribers (Pro, Plus, Go, Business), then will reach free and offline users. Enterprise and Edu customers have a seven-day early access toggle, which is off by default. The distribution will be gradual over the coming days to maintain stability.
On the API, GPT-5.1 Instant will appear as gpt-5.1-chat-latest and GPT-5.1 Thinking as GPT-5.1, both with adaptive reasoning. The goal is that you can start using the improvements in your apps soon.
Safety and transparency
OpenAI says there's an addendum in the system card with information about the safety approach for GPT-5.1. They also explain that the name 5.1 reflects significant improvements within the GPT-5 generation, and that future iterations will follow the same pattern.
For you, today
If you use ChatGPT for daily tasks, you'll notice warmer responses and better instruction-following. If you use it for technical work, the Thinking model promises clearer answers with less jargon. Not sure where to start? Try a couple of conversations with different styles and let the system suggest adjustments.
GPT-5.1 is an advance aimed at making AI adapt more to how you like to communicate, not just how much it knows. It's an update meant to be useful and enjoyable, and the good news is you can try and compare it during the transition period.
