Appendix B

Designing for Mobile Platforms

For a long time, desktop PCs accounted for the vast majority of the traffic that a typical website was likely to receive. It was relatively safe to simply ignore mobile users — they made up a tiny percentage of the market and accepted that most sites would not display correctly on their devices. All this is changing, though, and the mobile users currently make up approximately 8 percent of the market — a figure that is rising every year. The days when mobile users were a minority who could be ignored are long gone.

In this appendix, you learn about a variety of methods for detecting mobile devices and serving up custom content to them. In this way, you can ensure that users on devices with lower bandwidth or smaller screens still experience a fast, usable interface.


It’s worth defining exactly what is meant by mobile platforms. Once upon a time, it was easy to distinguish these platforms. Cell phones had a screen of approximately 2 inches, whereas PCs had a screen of approximately 15 or 17 inches. However, today, a huge range of devices fall somewhere in between — laptops, netbooks, tablets, smartphones, PDAs — all with varying screen sizes, and (perhaps just as important) different resolutions. Simply designing a mobile version of your site for users who have a cell phone with a 2-inch display fails to accommodate those with, say, a netbook with a 7-inch display.

Table B-1 shows some of the most common mobile ...

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