• Peter-Paul Koch
  • Owner QuirksMode.org
  • Twitter

Peter-Paul Koch is a mobile platform strategist, consultant, and trainer in Amsterdam, the Netherlands. He specialises in HTML, CSS, JavaScript, and mobile browser compatibility.

Nowadays he mostly concentrates on the two things that are really different on mobile/touchscreen devices: the touch events and the three mobile viewports.

He relishes the fact that web developers have no clue what he's talking about, and are forced to pay him boatloads of money to find out.


  • The Mobile Viewports
  • Time: 4:00pm - 4:50pm | Room: Grand C

Viewports are hard. Don't let anyone tell you they aren't. Although desktop browsers have only one, and it works pretty intuitively, mobile and tablet browsers have three. And sometimes they don't work intuitively - or at all.

What are the three viewports? (Spoiler: layout, visual, and ideal.) Why do we need all three? Why does responsive design work? (Not how. Why.) What happens when you set the meta viewport? How do browsers go wrong? (Spoiler: in plenty of innovative ways.)

And what about resolution, or DPR? (Spoiler: it is not what you think it is.)

In this session PPK, who spent more time on the mobile viewport than anyone not working for a browser vendor, answers these questions and more.