left CSS property

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;
<section id="default-example">
  <div class="example-container">
    <div id="example-element">I am absolutely positioned.</div>
    <p>
      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.
    </p>
  </div>
</section>
.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
/* <length> values */
left: 3px;
left: 2.4em;
left: anchor(--my-anchor 50%);
left: calc(anchor-size(--my-anchor inline, 100px) * 2);

/* <percentage>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

<length>

A negative, null, or positive <length>:

<percentage>

A <percentage> of the containing block's width.

auto

Specifies that:

Description

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

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                 |
  <length-percentage>  |
  <anchor()>           |
  <anchor-size()>      

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

<anchor()> = 
  anchor( <anchor-name>?                  &&
  <anchor-side> , <length-percentage>? )  

<anchor-size()> = 
  anchor-size( [ <anchor-name> || <anchor-size> ]? , <length-percentage>? )  

<anchor-name> = 
  <dashed-ident>  

<anchor-side> = 
  inside        |
  outside       |
  top           |
  left          |
  right         |
  bottom        |
  start         |
  end           |
  self-start    |
  self-end      |
  <percentage>  |
  center        

<anchor-size> = 
  width        |
  height       |
  block        |
  inline       |
  self-block   |
  self-inline

Examples

undefined

Positioning elements

HTML

html
<div id="wrap">
  <div id="example_1">
    <pre>
      position: absolute;
      left: 20px;
      top: 20px;
    </pre>
    <p>
      The only containing element for this div is the main window, so it
      positions itself in relation to it.
    </p>
  </div>

  <div id="example_2">
    <pre>
      position: relative;
      top: 0;
      right: 0;
    </pre>
    <p>Relative position in relation to its siblings.</p>
  </div>

  <div id="example_3">
    <pre>
      float: right;
      position: relative;
      top: 20px;
      left: 20px;
    </pre>
    <p>Relative to its sibling div above, but removed from flow of content.</p>

    <div id="example_4">
      <pre>
        position: absolute;
        bottom: 10px;
        right: 20px;
      </pre>
      <p>Absolute position inside of a parent with relative position</p>
    </div>

    <div id="example_5">
      <pre>
        position: absolute;
        right: 0;
        left: 0;
        top: 200px;
      </pre>
      <p>Absolute position with both left and right declared</p>
    </div>
  </div>
</div>

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

See also