OpenAI introduces GPT-5.5 Instant as the new default model for ChatGPT

May 5, 2026

AI Summary

OpenAI has launched GPT-5.5 Instant, replacing the previous GPT-5.3 Instant as the default model for ChatGPT. The new model aims to reduce inaccuracies in sensitive fields and offers enhanced context management features for personalized responses.

OpenAI released GPT-5.5 Instant, which will serve as the default model for ChatGPT, replacing GPT-5.3 Instant.
The new model is designed to minimize hallucinations in critical areas like law, medicine, and finance while maintaining low latency.
GPT-5.5 Instant scored 81.2 on the AIME 2025 math test, significantly higher than the 65.4 score of its predecessor.
It also outperformed GPT-5.3 on the MMMU-Pro multimodal reasoning benchmark, achieving a score of 76.0 compared to 69.2.
The model features improved context management, allowing it to reference past conversations and files for more personalized answers, initially available to Plus and Pro users on the web.
OpenAI plans to extend this feature to Free, Go Business, and enterprise users in the coming weeks.
Users can view and manage memory sources used for generating answers, including the ability to delete outdated sources or correct inaccuracies.
The GPT-5.5 model will be accessible via API as 'chat-latest,' with GPT-5.3 available for paid users for three months.
OpenAI previously faced backlash for retiring its GPT-4o model, which some users felt a strong connection to, leading to petitions against its withdrawal.

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OpenAI introduces GPT-5.5 Instant as the new default model for ChatGPT

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