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Julian Hurley
3,133 PointsBenefit of using 'ems' over 'px'
I just can't see it. Initially, I thought 'ems' changed relative to the size of the browser window, but now I see they stay the same. just like px, so what's the advantage?
2 Answers
James Barnett
39,199 Pointsem are a relative unit of measure unlike say pixels, they are relative to their parent font size. The term em comes from the width & height of a capital M in the specified typeface multiplied by their parent font size.
What's great about ems is they let you stick to a typographic scale, so your headings can be a multiple of your body font size and any type you need smaller is a fraction of your body font size. ems are recommended to only be used for font size, not for any structural sizing.
You can read up about ems in the blog post taking the erm out of ems.
jeff creamer
23,733 PointsHey Julian, ems are scalable, as you've noted, but also relative to the value of the inherited font-size. Sometimes we can be on a site whose font-size is in ems but not see a change in the size of the text when we make the browser window larger or smaller. A site coded in ems is ready to scale, though.