OpenAI:

OpenAI launches GPT-5.5 Instant, which it says is smarter, with more accurate and personalized responses, replacing GPT-5.3 Instant as ChatGPT's default model  —  We're updating ChatGPT's default model, available to everyone, to be smarter and more accurate, with clearer, more concise answers that feel better tailored to you.

OpenAI:

OpenAI launches GPT-5.5 Instant, which it says is smarter, with more accurate and personalized responses, replacing GPT-5.3 Instant as ChatGPT's default model  —  We're updating ChatGPT's default model, available to everyone, to be smarter and more accurate, with clearer, more concise answers that feel better tailored to you.

Source: TechMeme
Source Link: https://www.techmeme.com/260505/p34#a260505p34