Web/API/URL/URL

The URL() constructor returns a newly created URL object representing the URL defined by the parameters.

If the given base URL or the resulting URL are not valid URLs, the JavaScript TypeError exception is thrown.

Note: This feature is available in Web Workers.

Syntax

const url = new URL(url [, base])

Parameters

url: A USVString representing an absolute or relative URL. If url is a relative URL, base is required, and will be used as the base URL. If url is an absolute URL, a given base will be ignored.
base Optional: A USVString representing the base URL to use in cases where url is a relative URL. If not specified, it defaults to undefined.

Note: The url and base arguments will each be stringified from whatever value you pass, just like with other Web APIs that accept USVString. In particular, you can use an existing URL object for either argument, and it will stringify to the object's href property.

Exceptions

Exception	Explanation
`TypeError`	`url` (in the case of absolute URLs) or `base` + `url` (in the case of relative URLs) is not a valid URL.

Examples

// Base urls
let m = 'https://developer.mozilla.org';
let a = new URL("/", m);                                // => 'https://developer.mozilla.org/'
let b = new URL(m);                                     // => 'https://developer.mozilla.org/'

        new URL('en-US/docs', b);                      // => 'https://developer.mozilla.org/en-US/docs'
let d = new URL('/en-US/docs', b);                     // => 'https://developer.mozilla.org/en-US/docs'
        new URL('/en-US/docs', d);                     // => 'https://developer.mozilla.org/en-US/docs'
        new URL('/en-US/docs', a);                     // => 'https://developer.mozilla.org/en-US/docs'
        
        new URL('/en-US/docs', "https://developer.mozilla.org/fr-FR/toto");
                                                       // => 'https://developer.mozilla.org/en-US/docs'
                                                       
        new URL('/en-US/docs', '');                    // Raises a TypeError exception as '' is not a valid URL
        new URL('/en-US/docs');                        // Raises a TypeError exception as '/en-US/docs' is not a valid URL
        new URL('http://www.example.com', );           // => 'http://www.example.com/'
        new URL('http://www.example.com', b);          // => 'http://www.example.com/'

        new URL("//foo.com", "https://example.com")    // => 'https://foo.com' (see relative URLs)

Specification

Specification	Status	Comment
URLThe definition of 'URL.URL()' in that specification.	Living Standard	Initial definition.

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`URL()` constructor	Chrome Full support 19	Edge Full support 12	Firefox Full support 26	IE No support No	Opera Full support 15	Safari Partial support 6 Notes' Partial support 6 Notes' Notes' In Safari 14 and earlier, calling the `URL` constructor with a base URL whose value is `undefined` causes Safari to throw a `TypeError`; see WebKit bug 216841.	WebView Android Full support ≤37	Chrome Android Full support 25	Firefox Android Full support 26	Opera Android Full support 14	Safari iOS Partial support 6 Notes' Partial support 6 Notes' Notes' In Safari 14 and earlier, calling the `URL` constructor with a base URL whose value is `undefined` causes Safari to throw a `TypeError`; see WebKit bug 216841.	Samsung Internet Android Full support 1.5

Legend

Full support: Full support
Partial support: Partial support
No support: No support
See implementation notes.': See implementation notes.