URI.js is a javascript library for working with URLs. It offers a "jQuery-style" API (Fluent Interface, Method Chaining) to read and write all regular components and a number of convenience methods like .directory() and .authority().




NOTE: The npm package name changed to urijs

I always want to shoot myself in the head when looking at code like the following:

var url = "http://example.org/foo?bar=baz";
var separator = url.indexOf('?') > -1 ? '&' : '?';

url += separator + encodeURIComponent("foo") + "=" + encodeURIComponent("bar");

Things are looking up with URL and the URL spec but until we can safely rely on that API, have a look at URI.js for a clean and simple API for mutating URIs:

var url = new URI("http://example.org/foo?bar=baz");
url.addQuery("foo", "bar");

URI.js is here to help with that.

API Example

// mutating URLs
    // -> http://rodneyrehm@example.org/foo.html?hello=world
    // -> http://example.org/foo.html?hello=world
    // -> http://example.org/bar/foo.html?hello=world
    // -> http://example.org/bar/foo.xml?hello=world
    // -> http://example.org/bar/foo.xml
    // -> http://example.com/bar/foo.xml
  .query({ foo: "bar", hello: ["world", "mars"] });
    // -> http://example.com/bar/foo.xml?foo=bar&hello=world&hello=mars

// cleaning things up
    // -> ?foo=bar&foo=baz

// working with relative paths
    // -> ./baz.html

    // -> ../baz.html
    // -> /foo/bar/baz.html

// URI Templates
URI.expand("/foo/{dir}/{file}", {
  dir: "bar",
  file: "world.html"
// -> /foo/bar/world.html

See the About Page and API Docs for more stuff.

Using URI.js

URI.js (without plugins) has a gzipped weight of about 7KB - if you include all extensions you end up at about 13KB. So unless you need second level domain support and use URI templates, we suggest you don't include them in your build. If you don't need a full featured URI mangler, it may be worth looking into the much smaller parser-only alternatives listed below.

URI.js is available through npm, bower, bowercdn, cdnjs and manually from the build page:

# using bower
bower install uri.js

# using npm
npm install urijs


I guess you'll manage to use the build tool or follow the instructions below to combine and minify the various files into URI.min.js - and I'm fairly certain you know how to <script src=".../URI.min.js"></script> that sucker, too.

Node.js and NPM

Install with npm install urijs or add "urijs" to the dependencies in your package.json.

// load URI.js
var URI = require('urijs');
// load an optional module (e.g. URITemplate)
var URITemplate = require('urijs/src/URITemplate');

    // -> ../baz.html


Clone the URI.js repository or use a package manager to get URI.js into your project.

  paths: {
    urijs: 'where-you-put-uri.js/src'

require(['urijs/URI'], function(URI) {
  console.log("URI.js and dependencies: ", URI("//amazon.co.uk").is('sld') ? 'loaded' : 'failed');
require(['urijs/URITemplate'], function(URITemplate) {
  console.log("URITemplate.js and dependencies: ", URITemplate._cache ? 'loaded' : 'failed');


See the build tool or use Google Closure Compiler:

// ==ClosureCompiler==
// @compilation_level SIMPLE_OPTIMIZATIONS
// @output_file_name URI.min.js
// @code_url http://medialize.github.io/URI.js/src/IPv6.js
// @code_url http://medialize.github.io/URI.js/src/punycode.js
// @code_url http://medialize.github.io/URI.js/src/SecondLevelDomains.js
// @code_url http://medialize.github.io/URI.js/src/URI.js
// @code_url http://medialize.github.io/URI.js/src/URITemplate.js
// ==/ClosureCompiler==


Documents specifying how URLs work:

Informal stuff

How other environments do things

Discussion on Hacker News

Forks / Code-borrow

  • node-dom-urls passy's partial implementation of the W3C URL Spec Draft for Node
  • urlutils cofounders' window.URL constructor for Node


If you don't like URI.js, you may like one of the following libraries. (If yours is not listed, drop me a line…)


URL Manipulation

URL Parsers

URI Template



Contains Code From


URI.js is published under the MIT license. Until version 1.13.2 URI.js was also published under the GPL v3 license - but as this dual-licensing causes more questions than helps anyone, it was dropped with version 1.14.0.


moved to Changelog