What is fingerprinting?
Fingerprinting is a technique, outlined in the research by Electronic Frontier Foundation, of anonymously identifying a web browser with accuracy of up to 94%.
A browser is queried for its agent string, screen color depth, language, installed plugins with supported mime types, timezone offset and other capabilities, such as local storage and session storage. Then these values are passed through a hashing function to produce a fingerprint that gives weak guarantees of uniqueness.
No cookies are stored to identify a browser.
It's worth noting that a mobile share of browsers is much more uniform, so fingerprinting should be used only as a supplementary identifying mechanism there.
bower install fingerprint
npm install fingerprintjs
note the trailing js in the name
If you're on Rails, add this to your Gemfile
After that you can add the file to sprockets:
//= require fingerprint
Just copy the
fingerprint.js file to your js directory.
var fingerprint = ;
If you want to use canvas fingerprinting pass the
canvas: true option
var fingerprint = canvas: true;
According to the above Pixel Perfect research, it should further increase the accuracy of fingerprinting.
Note for IE9: in order to use the canvas fingerprinting on IE9, the html must have a valid html5 declaration:
If you want to use the screen resolution in calculating the fingerprint, pass the
screen_resolution: true option
var fingerprint = screen_resolution: true;
Incognito mode (Chrome) or Private mode (Firefox)
Fingerprint generates identical output in regular and private modes, i.e. the reporting will identify a private mode browser as usual.
IE 6, IE 7, IE 8, IE 9, IE 10, IE 11
Detecting the plugins information is very important in building the fingerprint.
In IE (surprise) it is not possible to just query the list of plugins, their mime types, etc. Instead, one must use special probing code to detect each individual plugin, because all plugins are ActiveX controls in IE.
If you want to query the IE plugins info to further diversify the fingerprinting process, pass the
ie_activex: true option.
This will detect following plugins:
- Adobe Reader
- Adobe Flash Player
- Apple QuickTime
- Real player (all versions)
- Shockwave player
- Windows Media Player
- Microsoft Silverlight
- Skype ClickToCall
Note that this process is safe for other browsers, and the
ie_activex options will be ignored.
Using custom hashing function
var my_hasher = value seed return valuelength % seed; ;var fingerprint = hasher: my_hasher;
or pass the hashing function as is:
var my_hasher = value seed return valuelength % seed; ;var fingerprint = my_hasher;
Running specs manually is just opening the
Running specs from the command line or in CI requires phantomjs in your
cd specs phantomjs lib/phantom-jasmine/run_jasmine_test.coffee test_runner.html
The example is in
To build the project, run
grunt command. This will run the jshint and uglify the code into
Running specs with grunt is not implemented but is on my todo list.
To minify the file I recommend using uglifyjs(requires node.js) If you don't have it installed, install it with:
npm -g install uglify-js
Then run the minification with:
uglifyjs fingerprint.js > fingerprint.min.js -mc
-mc tells uglifier to (m)angle and (c)ompress the input code.
If you don't have node.js installed on your machine, you can create a minified version of the library with online services, such as Google Closure compiler
This code is MIT licenced:
Copyright (c) 2013 Valentin Vasilyev
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.