Check out the latest documentation.


These pages show you how to set up and use the 51Degrees device detection API. For more information on how device detection works and can benefit you, please visit our Device Detection Page . If you’re using our cloud based device detection, you should refer to the Cloud API Documentation pages . All source code, and the free Lite data, is licensed under the Mozilla Public License version 2 .

Get Going With Our Tutorials

Getting started example of using 51Degrees device detection. The example shows how to:

  1. Set the configuration using a json object

    var config = {"dataFile" : "../data/51Degrees-LiteV3.2.dat",
                  "properties" : "IsMobile",
                  "cacheSize" : 10000,
                  "poolSize" : 4
  2. Instantiate the 51Degrees device detection provider with this connfiguration

    var provider = new fiftyonedegrees.provider(config);
  3. Produce a match for a single HTTP User-Agent header

    var match = provider.getMatch(userAgent);

  4. Extract the value of the IsMobile property


Full Source File
// Include 51Degrees.
var fiftyonedegrees = require("fiftyonedegreescore");

// Set the config.
var config = {"dataFile" : require("fiftyonedegreeslitepattern"),
              "properties" : "IsMobile",
              "cacheSize" : 10000,
              "poolSize" : 4,
              "stronglyTyped": false

// User-Agent string of an iPhone mobile device.
var mobileUserAgent = "Mozilla/5.0 (iPhone; CPU iPhone OS 7_1 like Mac OS X) AppleWebKit/537.51.2 (KHTML, like Gecko) 'Version/7.0 Mobile/11D167 Safari/9537.53";

// User-Agent string of Firefox Web browser version 41 on desktop.
var desktopUserAgent = "Mozilla/5.0 (Windows NT 6.3; WOW64; rv:41.0) Gecko/20100101 Firefox/41.0";

// User-Agent string of a MediaHub device.
var mediaHubUserAgent = "Mozilla/5.0 (Linux; Android 4.4.2; X7 Quad Core Build/KOT49H) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/ Safari/537.36";

console.log("Starting Getting Started Example.");

Initialises the device detection provider with settings from the config.
By default this will use the packaged Lite data file. For more info see:
<a href="">compare data options
var provider = new fiftyonedegrees.provider(config);

// Carries out a match with a mobile User-Agent.
console.log("\nMobile User-Agent: " + mobileUserAgent);
var match = provider.getMatch(mobileUserAgent);
console.log("   IsMobile: " + match.IsMobile);

// Carries out a match with a desktop User-Agent.
console.log("\nDesktop User-Agent: " + desktopUserAgent);
var match = provider.getMatch(desktopUserAgent);
console.log("   IsMobile: " + match.IsMobile);

// Carries out a match with a MediaHub User-Agent.
console.log("\nMediaHub User-Agent: " + mediaHubUserAgent);
var match = provider.getMatch(mediaHubUserAgent);
console.log("   IsMobile: " + match.IsMobile);

Full Source File

For more examples see the tutorial pages.


Node.js API loads device data from the data file into memory. The amount of memory required will depend on the data file you use.

How Does Device Detection Work

51Degrees device detection implementation does not rely on regular expressions, instead our algorithm looks at character positions in the HTTP User-Agent string and picks a set of signatures that represents the closest match. Then a set of four profiles (one for each of the following components: hardware, software, browser and crawler) is derived from those signatures. Properties and the corresponding values are then derived from those profiles. For more information and examples please see the How Device Detection Works  page.

Premium and Enterprise data files can benefit from automatic update capabilities. If you're a Lite user you can contact us for a free evaluation to experience the benefits of automatic updates and check out the  extra properties and features that come with Premium and Enterprise data files.

The latest Premium and Enterprise data files can be obtained from the downloads area.

Prerequisites and Compatibility

  • Node v6.5.0+
  • node-gyp
  • g++ 4.8.4+
  • SWIG 2.0+