WebAIM - Web Accessibility In Mind

E-mail List Archives

Re: Clickable/Tappable Area

for

From: Alastair Campbell
Date: Aug 23, 2013 8:50AM

On Fri, Aug 23, 2013 at 2:41 PM, Dave Merrill < <EMAIL REMOVED> >wrote:

> Must also depend on pixel density and screen size too, yes? Retina display
> have abut twice the density of other displays, and 50 px on a phone is
> different than 50 px on a 21" desktop display.


Not if you are talking about websites, devices generally even that out by
using "CSS pixels".

For example, a retina iPad has a device-pixel width of 1536px (in
portrait), but it reports a width of 768px for the purpose of rendering
page layouts.

My spangly new HTC one is a 1080p display (1280px wide in portait), but
reports a width of 360px.

Conversely, the browser on an Xbox reports a width of 1050px, although the
HD TV is 1920px wide.

The (CSS) pixel is actually your best bet for cross-device sizing:
http://alastairc.ac/2013/02/how-to-hold-your-ipad/

-Alastair