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CSS CSS Basics (2014) Understanding Values and Units Rem Units

justin light
justin light
4,921 Points
Posted by justin light
justin light
4,921 Points

Why don't I just use REM all the time?

If REM has all the benefits of being relative, but dont have the issue of compounding, why don't we just use REM's all the time? to prevent any issues later?

Or is there a downside to using REM over EM?

György Varga
György Varga
19,198 Points
György Varga
György Varga
19,198 Points

Hi!

Sometimes you want to stick with the same size in all window sizes and platforms, thats why we use px. For example: borders.

REM is relative to the font size of the root element (html element) and EM is relative to the font size of the element on which they are used. But here is more info about this: REMvsEM

Hope this helps!