OK, em Units Just Might Be Useful...

A bit of an about-face in my thinking has taken place recently.  A while back I wrote a blog post about how I think "em" units are worthless for their intended purpose, that is to say, scalable font design that can stretch or contract to accommodate changes to the font size.

I still think that em units are probably never going to see the kind of use that some standards advocates hope they will.  That's just one cold, hard truth of the web...  you can make the tool available, you can outline its benefits in no uncertain terms, but the majority of so-called developers and designers out there are either completely uninformed, don't care, or both.  So I don't believe that the usability portion of the em unit will ever be realized.

But after some thought, I did have a change of heart about the em unit itself.  You can do some very cool things with em units.  One example would be animation.  You could design a box so that it's dimensions are all em based, then with a little JavaScript you could animate its size doing nothing more than changing the font size of the containing element.

Don't get me wrong folks, I long for the days of resolution-independent, scalable design, vector graphics, and accessibility.  I just don't think em units fulfill the usability role very well, since most developers won't use them.  Now that all of the major browsers are implementing the zoom feature, I think that will make the em unit obsolete for that particular application.  And yes, zoom isn't perfect, its clear that will need to be refined too.  But the em unit is an incredibly useful feature, and I recant saying otherwise.