OpenAI makes GPT-5.5 Instant default ChatGPT model
openai released gpt-5.5 instant, replacing gpt-5.3 instant as the default chatgpt model. the new model scores 81.2 on aime 2025 math, up from 65.4, and emphasizes reduced hallucinations in law, medicine, and finance. context management features allowing source citation and editing are rolling out to plus and pro users now.
OpenAI released GPT-5.5 Instant, replacing GPT-5.3 Instant as the default ChatGPT model. The new model improves performance on the AIME 2025 math benchmark to 81.2 (up from 65.4) and the MMMU-Pro multimodal benchmark to 76.0 (up from 69.2). The release focuses on reducing hallucinations in sensitive sectors like law and medicine while maintaining low latency. The model introduces context management features, allowing it to reference past conversations, Gmail, and files to provide personalized answers. This citation feature is available immediately to Plus and Pro web users, with mobile and enterprise access planned for the coming weeks. Developers can access the model via the API as 'chat-latest', while the API for GPT-5.3 will remain available for paid users for three months.