Cover: original AI-generated concept illustration of a corrected form field and an outdated error message. It is not a working product screenshot.
Someone submits a form, sees an error, and corrects the field. Should the old error disappear as soon as they type, after they leave the field, or only after another submission?
I would separate a known error from a value that has not been checked yet. If the new value passes a local format check, keeping the old format error feels misleading. But clearing that message should not imply that a server-side check has succeeded.
A restored draft adds another wrinkle: yesterday's validation result may no longer apply. I would preserve the entered values, then recheck the relevant rules rather than restore every old red message as current.
There is a balance between timely feedback and interrupting someone on every keystroke.
When would you clear an existing validation error, and how would you distinguish “not checked yet” from “valid” without making the form noisy?