tech
May 5, 2026
OpenAI releases GPT-5.5 Instant, a new default model for ChatGPT
The company said the model reduces hallucination in sensitive areas such as law, medicine, and finance, while maintaining the low latency of its predecessor.
TL;DR
- OpenAI released GPT-5.5 Instant as the new default ChatGPT model, replacing GPT-5.3 Instant.
- The new model reduces hallucination in sensitive areas like law, medicine, and finance while maintaining low latency.
- GPT-5.5 Instant achieved higher scores on the AIME 2025 math test and the MMMU-Pro benchmark compared to its predecessor.
- Enhanced context management allows GPT-5.5 Instant to refer to past conversations, files, and Gmail for personalized answers, available to Plus and Pro users initially.
- ChatGPT will display memory sources for transparency, allowing users to manage or correct them.
- Developers can access GPT-5.5 via API as 'chat-latest'.
- OpenAI faced user backlash when previously withdrawing the GPT-4o model due to its perceived 'personality'.