The background
shorthand CSS property sets all background style properties at once, such as color, image, origin and size, or repeat method. Component properties not set in the background
shorthand property value declaration are set to their default values.
Constituent properties
This property is a shorthand for the following CSS properties:
background-attachment
background-clip
background-color
background-image
background-origin
background-position
background-repeat
background-size
Syntax
/* Using a <background-color> */ background: green; /* Using a <bg-image> and <repeat-style> */ background: url("test.jpg") repeat-y; /* Using a <box> and <background-color> */ background: border-box red; /* A single image, centered and scaled */ background: no-repeat center/80% url("../img/image.png"); /* Global values */ background: inherit; background: initial; background: revert; background: revert-layer; background: unset;
The background
property is specified as one or more background layers, separated by commas.
The syntax of each layer is as follows:
- Each layer may include zero or one occurrences of any of the following values:
<attachment>
<bg-image>
<position>
<bg-size>
<repeat-style>
- The
<bg-size>
value may only be included immediately after<position>
, separated with the '/' character, like this: "center/80%
". - The
<box>
value may be included zero, one, or two times. If included once, it sets bothbackground-origin
andbackground-clip
. If it is included twice, the first occurrence setsbackground-origin
, and the second setsbackground-clip
. - The
<background-color>
value may only be included in the last layer specified.
Values
<attachment>
-
See
background-attachment
. Default:scroll
. <box>
-
See
background-clip
andbackground-origin
. Default:border-box
andpadding-box
respectively. <background-color>
-
See
background-color
. Default:transparent
. <bg-image>
-
See
background-image
. Default:none
. <position>
-
See
background-position
. Default: 0% 0%. <repeat-style>
-
See
background-repeat
. Default:repeat
. <bg-size>
-
See
background-size
. Default:auto
.
The following three lines of CSS are equivalent:
background: none; background: transparent; background: repeat scroll 0% 0% / auto padding-box border-box none transparent;
Accessibility concerns
Browsers do not provide any special information on background images to assistive technology. This is important primarily for screen readers, as a screen reader will not announce its presence and therefore convey nothing to its users. If the image contains information critical to understanding the page's overall purpose, it is better to describe it semantically in the document.
- MDN Understanding WCAG, Guideline 1.1 explanations
- Understanding Success Criterion 1.1.1 | W3C Understanding WCAG 2.0
Examples
Setting backgrounds with color keywords and images
HTML
<p class="topbanner"> Starry sky<br /> Twinkle twinkle<br /> Starry sky </p> <p class="warning">Here is a paragraph</p> <p></p>
CSS
.warning { background: pink; } .topbanner { background: url("starsolid.gif") #99f repeat-y fixed; }