This project has moved and is read-only. For the latest updates, please go here.

Important: See 51degrees Web Site for latest documentation and FAQs

We're aiming to provide the simplest and most reliable method for .NET developers to integrate mobile devices with their existing and future web sites, which is why we're offering 51Degrees Device Data Lite for free use.

We have created an add-in module for .NET web sites called "Foundation" that'll automatically determine if a mobile device is accessing the site and redirect it to mobile specific content. Our add-in utilises the useragent string provided in the header of each HTTP request to identify the browser and mobile device making the request. The device database contains a useragent string for each known mobile device. When a new request is received, the API matches the useragent string to one in the database - either through a direct match or by finding the closest.

Once integrated into a web site, the module wil parse device data and store it in memory during the first request. Every time a mobile page is requested, .NET standard browser capabilities are enhanced using the mobile device data to override original values. Parameters such as screen width, screen height in pixels will be considerably more accurate, enabling you to create a web site that's more compelling and more reliable. Over 50 properties are available in our Enhanced data. In technical terms, when the Request.Browser object is queried, mobile device data is returned. It's that simple.

The following code placed in the Page_Load event returns the mobile device’s screen size:

int x = Request.Browser.ScreenPixelsWidth;

int y = Request.Browser.ScreenPixelsHeight;

With the 51degrees Device Data and Foundation installed these calls will return extremely accurate data when compared to the standard browser information provided by Microsoft.

But that's not all. Foundation supports redirection rules to automatically send requests from devices with defined properties, such as IsMobile = true, to different locations. Without writing a line of additional code you can create a mobile microsite accessible from your existing main home page. Read the User Guide to find out more.

We would like to hear about your experiences using Foundation either via our forum or by contacting us directly.

Select one of the following headings to read more.

Last edited Aug 14, 2014 at 5:13 PM by ThomasHolmes, version 34


nitinjain26 Nov 7, 2012 at 9:41 AM 
I am using Lite version for my testing purposes. But with sample .NET code provided, in the current device tab it says ScreenPixelsHeight = Unknown and ScreenPixelsWidth = Unknown. Although lite version should have given correct values.

evoskuil Oct 18, 2012 at 10:37 PM 
The download links for the package appear to be broken.

ThomasHolmes Sep 1, 2011 at 4:37 PM 
@torbenrohde - I'm not sure what went wrong with the site then... but it seems fixed now and the unfortunate eternal loopishness is just a distant, unpleasant memory.

torbenrohde Aug 30, 2011 at 9:05 AM 
@ThomasHolmes: The post you mentioned "51Degrees-mobi-Mobile-Detection-Outside-of-IIS" was just what I was looking for - but the HTTP version sends a 301 pointing to the HTTPS version, and the HTTPS version sends a Refresh header pointing back to the HTTP version... the circle of eternal loopishness is complete :o)

ThomasHolmes Aug 24, 2011 at 2:44 PM 
@imcfarlin - We have introduced this functionality in Look at the code sample on the downloads page or see a guide on our website at

lmcfarlin Apr 1, 2011 at 4:42 PM 
Is there a simple way to use the foundation .dll in a project where I do not have a Request object? In my case, I simply want to use the fuzzy string-matching and WURFL lookup capabilities to take a user-agent and match it up to a WURFL device outside of the context of a web application.

Y2KPRABU Feb 4, 2011 at 11:06 AM 
I have created a dependent project here , which helps in displaying the capabilities in a html user friendly way