CSS selector costs
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Connor Clark
Published: Oct 8, 2025
If recalculate style costs remain high, selector optimization can reduce them. Optimize the selectors with both high elapsed time and high slow-path percentages. Simpler selectors, fewer selectors, a smaller DOM, and a shallower DOM will all reduce matching costs.
How to pass this insight
This insight always passes, but may still show for informational purposes.
It only appears in the DevTools Performance panel when the setting Enable CSS selector stats (slow) is on.
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