left

Baseline Widely available *

This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.

* Some parts of this feature may have varying levels of support.

The left CSS property participates in specifying the horizontal position of a positioned element. This inset property has no effect on non-positioned elements.

Try it

left: 0;
left: 4em;
left: 10%;
left: 20px;
I am absolutely positioned.

As much mud in the streets as if the waters had but newly retired from the face of the earth, and it would not be wonderful to meet a Megalosaurus, forty feet long or so, waddling like an elephantine lizard up Holborn Hill.

.example-container {
  border: 0.75em solid;
  padding: 0.75em;
  text-align: left;
  position: relative;
  width: 100%;
  min-height: 200px;
}

#example-element {
  background-color: #264653;
  border: 4px solid #ffb500;
  color: white;
  position: absolute;
  width: 140px;
  height: 60px;
}

Syntax

css
/*  values */
left: 3px;
left: 2.4em;
left: anchor(--myAnchor 50%);
left: calc(anchor-size(--myAnchor inline, 100px) * 2);

/* s of the width of the containing block */
left: 10%;

/* Keyword value */
left: auto;

/* Global values */
left: inherit;
left: initial;
left: revert;
left: revert-layer;
left: unset;

Values

A negative, null, or positive :

  • for absolutely positioned elements, it represents the distance to the left edge of the containing block.
  • for anchor-positioned elements, the anchor() function resolves to a value relative to the position of the associated anchor element's left or right edge (see Using inset properties with anchor() function values), and the anchor-size() function resolves to a value relative to the associated anchor element's width or height (see Setting element position based on anchor size).
  • for relatively positioned elements, it represents the distance that the element is moved to the right of its normal position.

A of the containing block's width.

auto

Specifies that:

  • for absolutely positioned elements, the position of the element is based on the right property, while width: auto is treated as a width based on the content; or if right is also auto, the element is positioned where it should horizontally be positioned if it were a static element.
  • for relatively positioned elements, the distance of the element from its normal position is based on the right property; or if right is also auto, the element is not moved horizontally at all.

Description

The effect of left depends on how the element is positioned (i.e., the value of the position property):

  • When position is set to absolute or fixed, the left property specifies the distance between the element's outer margin of left edge and the inner border of left edge of its containing block. (The containing block is the ancestor to which the element is relatively positioned.) If the positioned element has an associated anchor element, and the property value includes an anchor() function, left positions the left edge of the positioned element relative to the position of the specified edge. The left property is compatible with the left, right, start, end, self-start, self-end, center, and values.
  • When position is set to relative, the left property specifies the distance the element's left edge is moved to the right from its normal position.
  • When position is set to sticky, the left property is used to compute the sticky-constraint rectangle.
  • When position is set to static, the left property has no effect.

When both left and right are defined, and width constraints don't prevent it, the element will stretch to satisfy both. If the element cannot stretch to satisfy both, the position of the element is overspecified. When this is the case, the left value has precedence when the container is left-to-right; the right value has precedence when the container is right-to-left.

Formal definition

Initial valueauto
Applies topositioned elements
Inheritedno
Percentagesrefer to the width of the containing block
Computed valueif specified as a length, the corresponding absolute length; if specified as a percentage, the specified value; otherwise, auto
Animation typea length, percentage or calc();

Formal syntax

left = 
auto |
|
|


=
|


=
anchor( ? &&
, ? )

=
anchor-size( [ || ]? , ? )

=


=
inside |
outside |
top |
left |
right |
bottom |
start |
end |
self-start |
self-end |
|
center

=
width |
height |
block |
inline |
self-block |
self-inline

Examples

Positioning elements

HTML

html
      position: absolute;
      left: 20px;
      top: 20px;
    

The only containing element for this div is the main window, so it positions itself in relation to it.

      position: relative;
      top: 0;
      right: 0;
    

Relative position in relation to its siblings.

      float: right;
      position: relative;
      top: 20px;
      left: 20px;
    

Relative to its sibling div above, but removed from flow of content.

        position: absolute;
        bottom: 10px;
        right: 20px;
      

Absolute position inside of a parent with relative position

        position: absolute;
        right: 0;
        left: 0;
        top: 200px;
      

Absolute position with both left and right declared

CSS

css
#wrap {
  width: 700px;
  margin: 0 auto;
  background: #5c5c5c;
}

pre {
  white-space: pre-line;
  word-wrap: break-word;
}

#example_1 {
  width: 200px;
  height: 200px;
  position: absolute;
  left: 20px;
  top: 20px;
  background-color: #d8f5ff;
}

#example_2 {
  width: 200px;
  height: 200px;
  position: relative;
  top: 0;
  right: 0;
  background-color: #c1ffdb;
}
#example_3 {
  width: 600px;
  height: 400px;
  position: relative;
  top: 20px;
  left: 20px;
  background-color: #ffd7c2;
}

#example_4 {
  width: 200px;
  height: 200px;
  position: absolute;
  bottom: 10px;
  right: 20px;
  background-color: #ffc7e4;
}
#example_5 {
  position: absolute;
  right: 0;
  left: 0;
  top: 100px;
  background-color: #d7ffc2;
}

Result

Specifications

Specification
CSS Positioned Layout Module Level 3
# insets

Browser compatibility

See also