GPT-5.5 Instant: smarter, clearer, and more personalized

OpenAI has released GPT-5.5 Instant, a new default model for ChatGPT that the company says is smarter, clearer and more personalized.

In a post published on May 5, OpenAI said GPT-5.5 Instant is rolling out as the new default in ChatGPT, replacing GPT-5.3 Instant. The company said the model is designed to give more concise, more natural responses while making better use of user context.

OpenAI also said internal evaluations found 52.5% fewer hallucinated claims on high-stakes prompts compared with GPT-5.3 Instant. It added that the update is meant to reduce gratuitous filler and make answers feel more direct.

The company introduced memory sources as part of the rollout, allowing users to see and manage the context ChatGPT uses for personalization.

TechCrunch, The Verge, Axios and 9to5Mac all reported the same launch on May 5, underscoring that this is now a live product change rather than a preview or research announcement.

The immediate questions are how quickly the rollout reaches all users and whether independent testing confirms OpenAI's factuality claims.