OpenAI stated that this new version makes fewer errors in critical areas such as law, healthcare, and finance. It also shows significant performance improvements, scoring 81.2% in the 2025 AIME mathematics exam, compared to GPT-5.3 Instant, which scored 65.4% on a similar test.
GPT-5.5 Instant achieved a score of 76% in the MMMU-Pro benchmark, which measures reasoning and analytical abilities across multiple domains. This marks a notable improvement from GPT-5.3 Instant, which scored 69.2%.
One of the key features of this new version is its enhanced memory capability. GPT-5.5 Instant can retrieve information from previous conversations, documents, and even Gmail to provide responses tailored to a user’s needs and preferences.
ChatGPT users will also be able to clearly see the sources of the information used by the system, allowing them to correct or remove outdated data. These data sources will remain private to the user, even if they share their conversation with others.
Developers can immediately start using this new version, while GPT-5.3 Instant will remain available for only three more months.
