The new model also achieved a score of 81.2 in the AIME 2025 math test, compared to 65.4 for the older model. It also outperformed its predecessor on the MMMU-Pro multimodal reasoning benchmark, with a score of 76 vs. 69.2.

The release placed a particular emphasis on context management. GPT-5.5 Instant can use its search tool to refer back to past conversations, files, and Gmail to give you more personalized answers. This feature will be available to Plus and Pro users on the web, with plans to roll it out to mobile soon. OpenAI said that it plans to extend access to this feature to Free, Go Business, and enterprise users in the coming weeks.

With this update, ChatGPT will also show memory sources across all models to help you understand where it generated the answers from. Users can delete outdated sources or correct them if the answer was wrong. Crucially, the company said that if you share a chat with someone, they won’t be able to see the memory sources.

For developers, the GPT-5.5 model will be available through API as “chat-latest,” with 5.3 available as an option for paid users for only three months.