Introducing GPT-5.3-Codex—the most powerful, interactive, and productive Codex yet
OpenAI Developer Community
February 5, 2026
I’m loving the coding, but not the speed. I don’t know if it’s a load issue, but it’s probably 3x slower than 5.2 codex in my experience so far today. Painfully slow. I’m hoping this is just a launch day issue.
Discussion in the ATmosphere