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Original fingerprintjs library was developed in 2012, it's now impossible to evolve it without breaking backwards compatibilty, so this project will be where all the new development happens.

This project will use significantly more sources for fingerprinting, all of them will be configurable, that is it should be possible to cherry-pick only the options you need or just enable them all.

I'm also paying special attention to IE plugins, popular in China, such as QQ, Baidu and others.

This project will not be backwards compatible with original fingerprintjs.

This project uses semver.


  • CDN: //cdn.jsdelivr.net/npm/fingerprintjs2@<VERSION>/dist/fingerprint2.min.js or https://cdnjs.com/libraries/fingerprintjs2
  • Bower: bower install fingerprintjs2
  • NPM: npm install fingerprintjs2
  • Yarn: yarn add fingerprintjs2


new Fingerprint2().get(function(result, components) {
  console.log(result) // a hash, representing your device fingerprint
  console.log(components) // an array of FP components

Note: You should not run fingerprinting directly on or after page load. Rather, delay it for a few milliseconds to ensure consistent fingerprints. See #307, #254, and others.

You can pass an object with options (all of which are optional):

var options = {swfPath: '/assets/FontList.swf', excludeUserAgent: true}
new Fingerprint2(options).get(function(result) {

Full list of options will be in the (https://github.com/Valve/fingerprintjs2/wiki/List-of-options) wiki page.

Flash font enumeration is disabled by default. JS code is used by default to get the list of available fonts.

The reason for this is that Flash will not work in incognito mode.

However, you can make the library to use Flash when detecting the fonts with:

excludeJsFonts: true


To use Flash font enumeration, make sure you have swfobject available. If you don't, the library will skip the Flash part entirely.

detectScreenOrientation option is true by default

To ensure consistent fingerprints when users rotate their mobile devices.

All fingerprinting sources are enabled by default, i.e. you don't need to explicitly configure the library to include them.
new Fingerprint2().get(function(result, components) {
  // this will use all available fingerprinting sources
  // components is an array of all fingerprinting components used

userDefinedFonts option

While hundreds of the most popular fonts are included in the extended font list, you may wish to increase the entropy of the font fingerprint by specifying the userDefinedFonts option as an array of font names, but make sure to call the Fingerprint function after the page load, and not before, otherwise font detection might not work properly and in a result returned hash might be different every time you reloaded the page.

new Fingerprint2({
  userDefinedFonts: ["Nimbus Mono", "Junicode", "Presto"]
}).get(function(result, components) {

preprocessor option

Function that is called with each component value that may be used to modify component values before computing the fingerprint. For example: strip browser version from user agent.

new Fingerprint2({
  preprocessor: function(key, value) {
    if (key == "user_agent") {
      var parser = new UAParser(value); // https://github.com/faisalman/ua-parser-js
      var userAgentMinusVersion = parser.getOS().name + ' ' + parser.getBrowser().name
      return userAgentMinusVersion
    } else {
      return value
}).get(function(result, components) {
  // user_agent component will contain string processed with our function. For example: Windows Chrome
  console.log(result, components)

View the fingerprint locally

You can view your browser fingerprint locally by starting a webserver and viewing the index.html page. Loading index.html from the filesystem won't work due to Flash's ExternalInterface security restrictions.

To start a web server you can try using one of the following:

  • Ruby 1.9.2+

    ruby -run -e httpd . -p 8080

  • Python 2.x

    python -m SimpleHTTPServer 8080

  • Python 3.x

    python -m http.server 8080

  • PHP 5.4+

    php -S

List of fingerprinting sources

  1. UserAgent
  2. Language
  3. Color Depth
  4. Screen Resolution
  5. Timezone
  6. Has session storage or not
  7. Has local storage or not
  8. Has indexed DB
  9. Has IE specific 'AddBehavior'
  10. Has open DB
  11. CPU class
  12. Platform
  13. DoNotTrack or not
  14. Full list of installed fonts (maintaining their order, which increases the entropy), implemented with Flash.
  15. A list of installed fonts, detected with JS/CSS (side-channel technique) - can detect up to 500 installed fonts without flash
  16. Canvas fingerprinting
  17. WebGL fingerprinting
  18. Plugins (IE included)
  19. Is AdBlock installed or not
  20. Has the user tampered with its languages 1
  21. Has the user tampered with its screen resolution 1
  22. Has the user tampered with its OS 1
  23. Has the user tampered with its browser 1
  24. Touch screen detection and capabilities
  25. Pixel Ratio
  26. System's total number of logical processors available to the user agent.
  27. Device memory
  28. Audio fingerprinting

By default, JS font detection will only detect up to 65 installed fonts. If you want to improve the font detection, you can pass extendedJsFonts: true option. This will increase the number of detectable fonts to ~500.

On my machine (MBP 2013 Core i5) + Chrome 46 the default FP process takes about 80-100ms. If you use extendedJsFonts option this time will increase up to 2000ms (cold font cache). This option can incur even more overhead on mobile Firefox browsers, which is much slower in font detection, so use it with caution on mobile devices.

To speed up fingerprint computation, you can exclude font detection (~ 40ms), canvas fingerprint (~ 10ms), WebGL fingerprint (~ 35 ms), and Audio fingerprint (~30 ms).

Many more fingerprinting sources will be implemented, such as

(in no particular order)

  • Multi-monitor detection,
  • Internal HashTable implementation detection
  • WebRTC fingerprinting
  • Math constants
  • Accessibility fingerprinting
  • Camera information
  • DRM support
  • Accelerometer support
  • Virtual keyboards
  • List of supported gestures (for touch-enabled devices)
  • Pixel density
  • Video and audio codecs availability
  • Audio stack fingerprinting

To recompile the FontList.swf file:

  • Download Adobe Flex SDK
  • Unzip it, add the bin/ directory to your $PATH (mxmlc binary should be in path)
  • Run make

My talk about the library (in Russian) on FrontEnd Conf 2015


License: MIT or Apache, whichever you prefer.


npm i moe-fingerprint

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