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
URL
The definition of 'URL.URL()' in that specification.
Living Standard Initial definition.

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
URL() constructorChrome Full support 19Edge Full support 12Firefox Full support 26IE No support NoOpera Full support 15Safari 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 ≤37Chrome Android Full support 25Firefox Android Full support 26Opera Android Full support 14Safari 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.

See also

  • The interface it belongs to: URL.