ChatGPT users may notice something different about the AI chatbot experience over the next few days. That’s because OpenAI is tweaking how its most-used model works.

OpenAI says it’s releasing a new version of its GPT-5.5 Instant model. The model originally arrived on May 5 (5/5) before receiving a separate behavior change.

At the time, the company said its default model in ChatGPT offered greater intelligence with less gratuitous emoji usage.

GPT-5.5 Instant was adjusted a few weeks later to be “easier to read, more natural in everyday conversations, and better paced in practical help tasks, with fewer overly long or bullet-heavy responses.”

Next, GPT-5.5 Instant is getting a new adjustment that OpenAI makes it “much more fun to talk to.”

“Our most-used model is now better at understanding the intent behind a question and adapting its response accordingly,” the company says. “It also handles complex constraints more reliably and makes shopping and local recommendations more useful and cohesive.”

OpenAI paid users can expect to see the newly updated GPT-5.5 Instant model arrive today before it reaches free users tomorrow.