iPhone double tap zoom – indistinguishable from magic

When I first saw Steve Jobs demo the iPhone’s double tap zoom feature on webpages I noticed something really neat – the zoom always seem to perfectly zoom to show a block of text.  There are 2 explanations

  1. It’s a fixed zoom level (e.g. 50%) that happened to work well in the demo (New York Times)
  2. It’s a smart zoom that knows what its zooming into and “does the right thing”

From Apples iPhone for Web Developers page: Design for Double Tap

“When the user double-taps a page, Safari on iPhone looks at the element that is double-tapped, and finds its closest block (as identified by elements like DIVOLULTABLE) or the image element (IMG) ancestor. If the found element is a block, Safari on iPhone zooms the content to fit the viewport width and then centers it. If it is an image, Safari on iPhone zooms to fit the image, and then centers it. If the block or image is already zoomed in, Safari on iPhone zooms out.”

That’s a beautiful fusion of technology and usability which to borrow a phrase from Arthur C. Clarke is sufficiently indistinguishable from magic.

Now I’m a cynic but I bet none of the iPhone contenders will manage to do this as well as Apple for several years – but expect the cheap, nasty and unsatisifying 50% zoom hack from competitors within months