The background-position-x CSS property sets the initial horizontal position for each background image. The position is relative to the position layer set by background-origin.
The value of this property is overridden by any declaration of the background or background-position shorthand properties applied to the element after it.
Syntax
/* 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: revert; background-position-x: revert-layer; background-position-x: unset;
The background-position-x property is specified as one or more values, separated by commas.
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>-
The offset of the given background image's left vertical edge from the background position layer's left vertical edge. (Some browsers allow assigning the right edge for offset).
<percentage>-
The offset of the given background image's horizontal position relative to the container. A value of 0% means that the left edge of the background image is aligned with the left edge of the container, and a value of 100% means that the right edge of the background image is aligned with the right edge of the container, thus a value of 50% horizontally centers the background image.
Formal definition
| Initial value | 0% |
|---|---|
| Applies to | all elements |
| Inherited | no |
| Computed value | A list, each item consisting of: an offset given as a computed <length-percentage> value, plus an origin keyword |
| Animation type | repeatable list |
Formal syntax
[ center | [ [ left | right | x-start | x-end ]? <length-percentage>? ]! ]#
Examples
Basic example
The following example shows a simple background image implementation, with background-position-x and background-position-y used to define the image's horizontal and vertical positions separately.
HTML
<div></div>
CSS
div {
width: 300px;
height: 300px;
background-color: skyblue;
background-image: url(https://mdn.dev/archives/media/attachments/2020/07/29/17350/3b4892b7e820122ac6dd7678891d4507/firefox.png);
background-repeat: no-repeat;
background-position-x: center;
background-position-y: bottom 10px;
}