Unless I am misreading the article, I think it is important to mention that (at least with a trackpad) this requires a two finger double-tap. This was actually mentioned in this hint from August:

http://hints.macworld.com/article.php?story=20110726090607949

The single-finger double-tap is correct for use with the Apple Magic Mouse.

Your right with that. I left that out. This was a follow-up to a post the day before about turning off Smart Zoom, http://hints.macworld.com/article.php?story=20130108131950239.


crarko even asked, "Do folks here make a lot of use of double-tap Smart zooming on a Mac? Knowing the circumstances where it proves useful would be a nice addition to the tip given here."

This is one use for Smart Zoom in Safari.