5.5 instant comes to ChatGPT today! imo it is a pretty big upgrade, i really like using it.

5.5 instant comes to ChatGPT today! imo it is a pretty big upgrade, i really like using it. Excited that we're updating the default model in ChatGPT today! 5.5 instant is a substantial improvement in intelligence, image perception, and factuality. It also updates the writing style to be a bit plainer and more straightforward. What was on your wishlist?

Source: Sam Altman (X) | 2026-05-05