Sound understanding of user devices is critical in today’s online world where so many devices allow users to access websites. Using a device detection solution is the only way to acquire this knowledge in real time, and use it to drive business decisions. In this article we’ll explain what device detection really is. We’ll also explore some technical difficulties which make accurate detection so tricky.

A great experience for all users on all devices

The term ‘mobile marketing’ was coined well over a decade ago to distinguish all marketing activities related to user engagement happening on mobile phones. These activities were considered fundamentally unique.

However, over the last several years technology has changed so much that the difference in capabilities between mobile devices, tablets,  laptops or desktop computers has diminished to the point where there’s no need to distinguish mobile marketing as a separate activity. Like it or not, your potential customers will try to learn about your products on many different devices, from PCs, to laptops, to tablets, to smartphones. Businesses now need to make sure they offer a coherent experience for their customers on all devices.

Device detection is essential to make this happen.

How does device detection work?

Device detection is based on analyzing the User-Agent string sent by the browser. User-Agent strings are defined in the HTTP standard which says that a User-Agent (UA) is made up of multiple ‘product tokens’ indicating the software and hardware characteristics of the device. The 'rules' involved creating UAs aren’t strict. Browser makers and hardware manufacturers (who are responsible for naming the hardware in the User-Agent) are free to conceal information about the device or the browser (this approach is known as ‘UA masquerading’). A device detection solution must be sophisticated enough to handle situations where the device masquerades as something else.

It is important not to mistake device detection for 'browser sniffing,' an outdated technique which has quite a bad reputation amongst developers.

Device detection is different from browser sniffing

When web standards were in their infancy, Netscape Navigator 2 (Mozilla) was the dominant browser offering more than competing IE 3. Instead of adjusting sites to IE’s limitations, web developers often blocked users via a keyword-based technique called browser sniffing. In response to this browser makers learned to outsmart the ‘sniffing’ technique by including as many browser names and other keywords in UAs as possible. This is one of the reasons why today the world of User Agent strings is still a mess.

Browser sniffing was considered a poor technique because it used an unreliable, inaccurate, keyword-based technique, and its primary goal was to force the user to switch to a different browser.

Device detection has little to do with old-school browser sniffing except for the fact that it is also based on analysing User Agent strings. Its aim is not to limit the UX or block certain kinds of browsers but to adjust UX by offering an optimal viewing experience on all devices.

What is device detection used for?

Device detection can be used for any application which requires an awareness of the device. If an online solution is based on device knowledge, it must use a technique to detect devices accessing web content.

One of the most popular applications of device detection is known as Adaptive Web Design (AWD), adaptive delivery or content adaptation. AWD is a design principle in which different markup is sent to different buckets of devices based on detection of devices accessing web content. Each set of markup creates a different, device-optimized experience. Here are 10 examples of high-profile, high-traffic websites using Adaptive Web Design.

Many RWD websites also use device detection to fine-tune the experience without redirecting users to a different HTML/CSS. This technique is called RESS. With server-side device detection it is possible to use detailed device knowledge to adapt those aspects of a responsive website that may create bottlenecks or degrade the experience on mobile devices. This typically relates to heavy images, scripts, menus, etc.

Device detection is also used to deliver advertising targeted at device level. In this case, device detection enables the ad server to send advertising campaigns to specific devices based on screen size, operating system, phone brand, phone model, or any of the device characteristic that the device database tracks.

The knowledge of user devices is widely used by website analytics platforms. Device detection can provide data for web analytics tool on all aspects of device use, such as device types (phone, tablet, desktop), device models, screen sizes, operating systems, etc. Thanks to this information, you may learn that, for example, Samsung Galaxy S4 delivers 12% conversion rate, while iPhone 6S delivers 23% conversion rate, which helps you make data-driven decisions on allocating advertising budget.