OpenAI Launches GPT-5.5 Instant for ChatGPT

OpenAI has launched GPT-5.5 Instant as the new default model for ChatGPT, replacing GPT-5.3 Instant. This update aims to significantly reduce AI hallucinations, particularly in sensitive areas like law, medicine, and finance, while maintaining low latency. The new model also shows improved performance on mathematics and multimodal reasoning benchmarks. Key features include enhanced personalization through context from past conversations, uploaded files, and connected Gmail accounts, initially for Plus and Pro users. OpenAI is also introducing 'memory sources' across all ChatGPT models, providing users with transparency and control over the information used for responses. GPT-5.5 Instant is rolling out to all ChatGPT users and is available via API as 'chat-latest', with GPT-5.3 Instant remaining accessible for paid users for three months before retirement. This move is crucial for OpenAI's consumer product strategy, impacting the largest share of ChatGPT usage and shifting it towards a more context-aware assistant.