OpenAI releases GPT-5.5 Instant as new default ChatGPT model

OpenAI has released GPT-5.5 Instant as the new default model in ChatGPT, replacing GPT-5.3 Instant.

In its May 5 product announcement, OpenAI said the update is designed to improve factuality, brevity and personalization. The company said GPT-5.5 Instant will be the default for all users and that paid users will keep access to GPT-5.3 Instant for three months.

OpenAI also said memory sources are now more visible, with controls that let users delete or correct the context ChatGPT uses for personalized responses. The company is pushing the feature as a way to make the assistant more tailored while giving users more oversight.

TechCrunch reported the same rollout on May 5, and The Verge followed with coverage on May 6. OpenAI's help-center page still shows some GPT-5.3 language, which appears to lag the product announcement rather than contradict it.

The immediate question is how quickly the default-model switch reaches all users and whether the promised accuracy and personalization gains hold up outside OpenAI's internal testing.

For now, the release marks another reset of ChatGPT's default experience and a stronger emphasis on user-specific context management.