[OpenAI: GPT-5.5 Instant Launches for All ChatGPT Users Starting Today] According to Jinshi reports, OpenAI announced that GPT-5.5 Instant is launching for all ChatGPT users starting today. For paid users, GPT-5.3 Instant will remain available for the next three months and can be accessed through model configuration settings, after which this version will officially retire. The memory source feature is being gradually rolled out to all ChatGPT consumer-tier users on the web and will soon be available on mobile.