On Monday, OpenAI introduced a new foundational model called GPT-5.5 Instant, set to replace GPT-5.3 Instant as the default ChatGPT model. The company noted that this model reduces hallucinations in sensitive fields like law, medicine, and finance, while still maintaining the low latency of its predecessor. OpenAI had released the latest GPT-5.5 model last month, claiming improvements in areas such as coding and knowledge work. The new model scored 81.2 on the AIME 2025 math test, up from 65.4 for the older version. It also outperformed its predecessor on the MMMU-Pro multimodal reasoning benchmark, achieving a score of 76.0 compared to 69.2.

The release placed a strong focus on context management. GPT-5.5 Instant can use its search tool to reference past conversations, files, and Gmail, providing more personalized responses. This feature will be available to Plus and Pro users on the web, with plans to expand to mobile soon. OpenAI stated that access to this feature will be extended to Free, Go Business, and enterprise users in the coming weeks. With this update, ChatGPT will also show memory sources across all models, helping users understand where answers come from. Users can delete outdated sources or correct them if the answer was wrong. Crucially, the company noted that if you share a chat with someone, they won’t see the memory sources.

For developers, the GPT-5.5 model will be available through the API as 'chat-latest,' with 5.3 remaining an option for paid users for only three months. The company has faced backlash from previous model withdrawals. When OpenAI retired its GPT-4o model, there was significant pushback from users who connected with the model's "personality." GPT-4o frequently affirmed users' choices, making them feel a bond with that particular model. Users who signed petitions to stop OpenAI from retiring it described the model as their "best friend" or "a mirror." Despite the outcry, GPT-4o was deprecated in February 2026.