Web/CSS/url

The <url> CSS data type denotes a pointer to a resource, such as an image or a font. URLs can be used in numerous CSS properties, such as background-image, cursor, and list-style.

URI or URL? There is a difference between a URI and a URL. A URI simply identifies a resource. A URL is a type of URI, and describes the location of a resource. A URI can be either a URL or a name (URN) of a resource.

In CSS Level 1, the url() functional notation described only true URLs. In CSS Level 2, the definition of url() was extended to describe any URI, whether a URL or a URN. Confusingly, this meant that url() could be used to create a <uri> CSS data type. This change was not only awkward but, debatably, unnecessary, since URNs are almost never used in actual CSS. To alleviate the confusion, CSS Level 3 returned to the narrower, initial definition. Now, url() denotes only true <url>s.

Syntax

The <url> data type is specified using the url() functional notation. It may be written without quotes, or surrounded by single or double quotes. Relative URLs are allowed, and are relative to the URL of the stylesheet (not to the URL of the web page).

If you choose to write the URL without quotes, use a backslash (\) before any parentheses, whitespace characters, single quotes (') and double quotes (") that are part of the URL.

<a_css_property>: url("http://mysite.example.com/mycursor.png")
<a_css_property>: url('http://mysite.example.com/mycursor.png')
<a_css_property>: url(http://mysite.example.com/mycursor.png)

Examples

A url used in the backgroun property

.topbanner {
  background: url("topbanner.png") #00D no-repeat fixed;
}

A url loading an image as a list bullet

ul {
  list-style: square url(http://www.example.com/redball.png);
}

Specifications

Specification	Status	Comment
CSS Values and Units Module Level 4The definition of '<url>' in that specification.	Editor's Draft
CSS Values and Units Module Level 3The definition of '<url>' in that specification.	Candidate Recommendation	No significant change from CSS Level 2 (Revision 1).
CSS Level 2 (Revision 1)The definition of '<uri>' in that specification.	Recommendation	No significant change from CSS Level 1.
CSS Level 1The definition of '<url>' in that specification.	Recommendation	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>`	Chrome Full support 1	Edge Full support 12	Firefox Full support 1	IE Full support 3	Opera Full support 3.5	Safari Full support 1	WebView Android Full support 1	Chrome Android Full support 18	Firefox Android Full support 4	Opera Android Full support 14	Safari iOS Full support 1	Samsung Internet Android Full support 1.0

Legend

Full support: Full support