Style invalidation

Working out which elements need styles recalculated after a change.

What is style invalidation?

Style invalidation is the browser working out which elements need their styles recalculated after something changes, such as a class being added.

document.body.classList.add("dark-mode");   // invalidates styles that depend on .dark-mode

Level: Master · More CSS terms at this level

Updated September 27, 2026