Identifying your mobile visitors from web stats

    As mobile browsers have moved from gimmick to the mainstream over the last few years the job of a web developer has had to evolve to service their needs. With full-featured mobile browsers replacing the cut-down early offerings we might have to worry less about our mobile users than we used to but we still have to ensure that they can use our sites with few problems.

    The problem with mobile platforms from a developer perspective is that there are so many of them in use. Testing a web site on the desktop is comparatively easy, once you’ve made it work in IE and Firefox, you’re unlikely to find any issues in Chrome, Safari or Opera so once you’ve given it the once-over on a Mac there’s not much left to do. By comparison it is almost impossible to have one of each of the plethora of mobile phone platforms so once you’ve looked at the iPhone, Android, and Opera browsers, with maybe Windows Mobile and Blackberry as well (assuming you are fortunate enough to know owners of all those handsets) you have little idea how the rest of your mobile users will experience your offering. In my case I have an Android phone and a Series 40 Nokia clamshell, and I borrow a friend's iPhone 3G when I need to test that platform.

    To shed some light on the matter you need to know the scale of the problem. So you go to your web stats or analytics package and look at the browser/OS combinations. If you’re lucky, your package will be capable of recognising smartphones, so you’ll pretty quickly see stats for visitors with iPhones, Android phones and maybe Blackberries. But a cursory glance at the detected user agents should tell you that is only the tip of the iceberg. A quick look at mine reveals a huge list of feature phones, some from well-known manufacturers like Nokia or Samsung and other devices I’ve never seen and in most cases never heard of.
    On my site I finally settled on looking at screen resolutions. I decided anything smaller than 640x480 had to be some kind of mobile device, so added those numbers to those of a few well-known larger-screened devices. The iPhone 4's 960x640 pixel display being a good example. In the end I found that around a tenth of a percent of my site's visitors were mobile users. This was less than I expected because I think the number of different user agents had led me to believe there would be more, however it tallied with the figures for browsers and OSs so I found it to be believable.