MDN wants to talk to developers like you: https://qsurvey.mozilla.com/s3/8d22564490d8

The background-position-x CSS property sets the initial horizontal position, relative to the background position layer defined by background-origin for each defined background image. For more information, see the background-position property, which has been widely supported.

/* Keyword values */
background-position-x: left;
background-position-x: center;
background-position-x: right;

/* <percentage> values */
background-position-x: 25%;

/* <length> values */
background-position-x: 0px;
background-position-x: 1cm;
background-position-x: 8em;

/* side-relative values */
background-position-x: right 3px;
background-position-x: left 25%;

/* Multiple values */
background-position-x: 0px, center;

/* Global values */
background-position-x: inherit;
background-position-x: initial;
background-position-x: unset;
Note: The value of this property is overridden by any declaration of the background or background-position shorthand properties applied to the element after the background-position-x CSS property.

Initial valueleft
Applies toall elements
Inheritedno
Percentagesrefer to width of background positioning area minus height of background image
Mediavisual
Computed valueA list, each item consisting of: an offset given as a combination of an absolute length and a percentage, plus an origin keyword
Animation typediscrete
Canonical orderthe unique non-ambiguous order defined by the formal grammar

Syntax

Values

left
Aligns the left edge of the background image with the left edge of the background position layer.
center
Aligns the center of the background image with the center of the background position layer.
right
Aligns the right edge of the background image with the right edge of the background position layer.
<length>
A <length> value defines the offset of the given background image's horizontal edge from the corresponding background position layer's horitzontal edge. If no edge is mentioned, it refers to the left edge.
<percentage>
A <percentage> value defining the offset of the given background image's horitzontal edge from the corresponding background position layer's horitzontal edge relative to its width. If no edge is given, it refers to the left edge by default.

Formal syntax

[ center | [ left | right | x-start | x-end ]? <length-percentage>? ]#

where
<length-percentage> = <length> | <percentage>

Specifications

Specification Status Comment
CSS Backgrounds and Borders Module Level 4
The definition of 'background-position-x' in that specification.
Editor's Draft Initial specification of longhand sub properties of background-position  to match longstanding implementations.

Browser compatibility

FeatureChromeFirefoxEdgeInternet ExplorerOperaSafariServo
Basic Support(Yes)49.0126(Yes)(Yes)?
Two-value syntax (support for offsets from any edge)(No)49.0129.0(No)(No)?
FeatureAndroidChrome for AndroidEdge mobileFirefox for AndroidIE mobileOpera AndroidiOS Safari
Basic Support(Yes)(Yes)(Yes)49.0???
Two-value syntax (support for offsets from any edge)(No)(No)(Yes)49.0?(No)(No)

See also

Document Tags and Contributors

 Last updated by: fscholz,