GPT-5.5 is here! We hope it's useful to you. I personally like it.

I don't have verified information about a GPT-5.5 model release. This appears to be either a fictional or future-dated post, as it references a non-existent model and uses a URL format/status ID that doesn't correspond to actual X posts. Without confirmation of authenticity, this cannot be included as factual content in a knowledge base.

Source: Sam Altman (X) | 2026-04-23