A while back now I wrote a short article on how to detect a mobile user by reading the user agent value from their browser (Link: http://www.mccran.co.uk/index.cfm/2010/6/4/Simple-Coldfusion-script-to-detect-if-a-user-is-on-a-Mobile-platform). I've since reversed my stand on doing this for a number of technical and User Experience based reasons.

This blog article is an exploration of those reasons.

I've been using a script like the one above to automatically detect mobile users and push them to a mobile specific version of the website they are on, but I've noticed a few issues around doing this.

1. Deep linking from search engines

You've all seen links from search engines that go directly to content pages deep within a site. Well as soon as you detect a users platform and redirect them their requested journey is broken. You are essentially intercepting their page request and pushing them somewhere else.

Try this link on a mobile device: http://uk.gamespot.com/features/6330617/deus-ex-human-revolution-walkthrough You'll notice that you get automatically pushed to their mobile site, but it is only to the home page not the page you actually want. Annoying isn't it.

2. Modern mobile platforms can easily handle full size websites

As I've documented on this site previously I use a Samsung Galaxy Tab 10.1. It is a great device and has a 10 inch screen (1280x800 screen resolution). This device is more than capable of displaying and interacting with full size websites. In fact it is a much better experience than using mobile optimised sites as they look quite poor on a screen that size.

Mobile optimised sites are aimed at devices with less processing power and smaller screens but the trend for Mobile phones and Tablet devices is that their hardware is getting faster, with faster processors and bigger, higher resolution screens. This makes quite a compelling argument for developers to focus less and less on building lightweight mobile optimised sites. I know that I've setup my tablet to always go to the full version of a site and not the mobile version.

3. User agents and screen resolutions are easily faked

One of the things I discovered using the mobile version of the Chrome browser is that you can quite easily edit the User Agent settings in the browser.(Link: http://www.mccran.co.uk/index.cfm/2011/9/25/Samsung-Galaxy-Tab-101-Switching-your-browser-from-mobile-view ) You can change the User Agent to a variety of platforms. After testing this out on one of my own platforms I can confirm that the device does appear as set in the User Agent, completely bypassing the detection script above.

4. Who am I to decide the users journey? Does it really a good User Experience?

Working more and more in the Accessibility and User Experience fields I've come to realise that allowing users the flexibility to consume your content in a way appropriate to them is the way to really foster engagement and repeat usage. Forcing users down a certain route or pushing them around your site based on technology decisions never results in a high quality user journey.

Allowing them to decide for themselves by giving them clear and obvious options like a navigation link to a mobile version of a site (and vice versa -a link to the full version on the mobile site) empowers the user and ensures that they are the ones in control, not the technology.