The GPT-5.1 upgrade brings significant improvements to both intelligence and conversational style, making ChatGPT smarter and more enjoyable to interact with. This release introduces two enhanced models: GPT-5.1 Instant and GPT-5.1 Thinking, each designed to better meet user needs.
GPT-5.1 Instant, the most-used model, is now warmer by default and more conversational. Early testing shows it often surprises users with its playfulness while remaining clear and useful. For example, when asked for relaxation tips, it provides personalized, empathetic responses:
🌬️ If your mind feels scattered
– Box breathing: Inhale for 4 counts, hold for 4, exhale for 4, hold for 4 — repeat 5 times.
– Name what you see: Pick out 5 things you can see, 4 you can touch, 3 you can hear, 2 you can smell, and 1 you can taste.
🎧 If you need to slow down
– Music reset: Put on something ambient or lo-fi.
– Step outside: Even 5 minutes of daylight resets cortisol levels.
🧘♂️ If you want to fully unwind
– Stretch the stress out: Roll your shoulders back, touch your toes, then lie on the floor with your legs up the wall.
– Warm shower or bath: Heat relaxes muscles and signals rest.
The model also excels at instruction following. When asked to always respond with six words, it consistently adheres to this constraint, demonstrating improved reliability.
GPT-5.1 Thinking, the advanced reasoning model, is now more efficient and easier to understand. It adapts thinking time dynamically—spending more time on complex problems and responding faster to simpler ones. On a representative distribution of tasks, it’s roughly twice as fast on the fastest tasks and twice as slow on the slowest, optimizing for thoroughness and speed as needed.
Responses are clearer, with less jargon and fewer undefined terms. For instance, when explaining baseball stats like BABIP and wRC+, it breaks them down in plain English:
- BABIP: Measures how often a ball in play falls for a hit, excluding home runs and strikeouts. Used to gauge luck vs. true skill.
- wRC+: A catch-all hitting stat that compares a hitter’s run creation to league average, adjusted for ballpark and era. 100 is average; every point above/below is a percentage better/worse.
The default tone is warmer and more empathetic. In response to a user spilling coffee before a meeting, it reassures:
“Hey — no, they didn’t. You’re rattled, so your brain is catastrophizing a tiny mishap. But honestly? People barely register this stuff. A coffee spill reads as ‘busy human,’ not ‘idiot.'”
This release also enhances customization. New tone options include Professional, Candid, and Quirky, alongside updated Default, Friendly, and Efficient styles. Users can fine-tune characteristics like conciseness, warmth, and emoji usage directly from settings, with changes applying across all chats immediately.
GPT-5.1 Instant and Thinking begin rolling out today, starting with paid users and expanding to free and logged-out users. The API will follow later this week. GPT-5 remains available under the legacy models dropdown for three months, allowing a smooth transition.
These updates make ChatGPT more capable and adaptable, fitting individual preferences while advancing both intelligence and usability.