OpenAI launches GPT-5.5 Instant with stronger personalization

OpenAI has updated ChatGPT’s default model to GPT5.5 Instant, describing it as smarter, clearer, and more personalized. The company says the new version is available to all ChatGPT users and is designed to deliver shorter, more accurate, and more natural responses. According to OpenAI, GPT5.5 Instant shows improved factual accuracy, including fewer hallucinated claims in internal tests on highstakes topics such as medicine, law, and finance. The model also performs better on tasks like image analysis, STEM questions, and deciding when web search may help answer a prompt. The update also expands personalization. ChatGPT can now use context from past chats, uploaded files, and connected Gmail accounts for eligible users, while a new memorysources feature shows which context was used to shape a response. OpenAI said the rollout begins May 5, 2026, with broader personalization features coming first to Plus and Pro users and expanding later to other plans.