OpenAI releases GPT-5.5 Instant, a new stable version of ChatGPT

On Monday, OpenAI released a new base version called GPT-5.5 Instant, which will replace GPT-5.3 Instant as the default ChatGPT version. The company said that this model reduces simulation in complex areas such as law, medicine, and finance, while maintaining the low latency of its predecessors.

OpenAI has been released the latest version of GPT-5.5 last month is a company that wants to improve areas such as writing and information.

The new model also scored 81.2 in the AIME 2025 math test, compared to 65.4 for the old model. It also outperformed its predecessor on the MMMU-Pro multimodal benchmark, with 76.0 vs 69.2.

This release put a lot of emphasis on product management. GPT-5.5 Instant can use its search tool to go back to chats, files, and Gmail to provide you with answers that are relevant to you. This feature will be available to Plus and Pro users online, with plans to roll it out to mobile soon. OpenAI said it plans to expand access to this feature to Free, Go Business, and enterprise users in the coming weeks.

With this update, ChatGPT will also include memory sources across all models to help you understand where they generated responses. Users can delete old sources or correct if the answer was wrong. Of course, the company said that when you share a chat with someone, they won’t be able to see where their memories are.

For developers, the GPT-5.5 version will be available via the API as a ‘chat-latest,’ while 5.3 is available as a subscription to paid users for three months only.

The company has done it met with opposition from the previous removal process. When OpenAI abandoned its version of GPT-4o, there was a huge backlash from the same users about the “personality” of the model. GPT-4o validates users’ choices regularly and this makes them feel connected to the brand. Users who signed petitions to prevent OpenAI from resigning described the model as their “best friend” or “mirror.” Despite the outcry, GPT-4o was withdrawn in February 2026.