OpenAI today pushed GPT-5.5 Instant out to all ChatGPT users, officially replacing GPT-5.3 Instant as the default model. The older 5.3 Instant will stick around for paying customers for another three months before being retired.
This update is all about deeper personalization — and transparency. GPT-5.5 Instant can now draw more intelligently on your past chats, uploaded files, and even connected Gmail data to tailor its responses. To give you some control over that, OpenAI also launched a new "Memory sources" feature. When a reply is personalized, the system will clearly show you which historical conversations or memory cards it referenced. You can view and delete outdated info right from that view.
The beefed-up personalization is available now for Plus and Pro users on the web, with plans to expand to free and enterprise accounts in the coming weeks. Meanwhile, the Memory sources feature is rolling out gradually to all consumer accounts.