Sticky headers in tall tables: helpful or just heavy?

Once a table passes ten or so rows, visitors lose track of what each column means. A sticky header keeps the labels visible while scrolling.

Arguments for:
— fewer scroll-ups to re-read column titles, which shows up as longer time on the table;
— on desktop the cost is negligible: a few lines of CSS with position: sticky.

Arguments against:
— on mobile a sticky header plus a sticky site nav plus a cookie banner leaves very little room for content;
— sticky elements inside scrolling containers behave inconsistently across browsers;
— if the table is short, the header never needs to stick, and the extra code adds nothing.

A practical guideline: enable sticky headers only when the table is taller than roughly two viewports, and only on screens wider than tablets. Below that, use the card layout, where headers are not needed at all.

And a note on the reverse: a sticky footer with the CTA at the bottom of a long table is a different feature. It is often more valuable than the sticky header and gets tested far less.