fingerprintjs

Fast browser fingerprint library. Written in pure JavaScript, no dependencies. By default uses Murmur hashing and returns a 32bit integer number. Hashing function can be easily replaced. Feather weight: only 1.2 KB when gzipped.

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.

Installation

Bower

bower install fingerprint

NPM

npm install fingerprintjs note the trailing js in the name

Ruby-on-Rails

If you're on Rails, add this to your Gemfile

gem 'fingerprintjs-rails' and

bundle install

After that you can add the file to sprockets:

//= require fingerprint

Manual

Just copy the fingerprint.js file to your js directory.

Usage

var fingerprint = new Fingerprint().get();

If you want to use canvas fingerprinting pass the canvas option

var fingerprint = new Fingerprint({canvas: true}).get;

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:

<!DOCTYPE html>

Using custom hashing function

var my_hasher = new function(value, seed){ return value.length % seed; }
var fingerprint = new Fingerprint({hasher: my_hasher}).get();

or pass the hashing function as is:

var my_hasher = new function(value, seed){ return value.length % seed; }
var fingerprint = new Fingerprint(my_hasher).get();

Running specs

Running specs manually is just opening the specs/test_runner.html

Running specs from the command line or in CI requires phantomjs in your PATH

cd specs

phantomjs lib/phantom-jasmine/run_jasmine_test.coffee test_runner.html

The example is in run.sh file.

Minification

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

Licence

This code is MIT licenced:

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.

andreypopp / fingerprintjs