CSS scaleX() Function

The CSS scaleX() function is used to scale elements in a two-dimensional space along the x-axis.

The scaleX() function scales an element based on the number/s that you provide as an argument.

Because it only scales along the x-axis, the element will be distorted if you use it alone (for example, without also using the scaleY() function to scale the y-axis).

Here's an example of scaling an element using scaleX():

<style>
  .scaled {
    transform-origin: top left;
    transform: scaleX(2);
  }
</style>

<img src="/pix/samples/9s.jpg" alt="Sample image">
<img class="scaled" src="/pix/samples/9s.jpg" alt="Sample image">

Removing `transform-origin`

In the previous example, I use transform-origin to adjust the origin of the transformation. Specifically, I use transform-origin: top left; so that the images don't overlap as a result of the scaling operation.

The default origin for the rotation is 50% 50% (i.e. the center). Therefore, if we remove this property, the image will transform based on this value.

So here's an example of what the scale operation might look like when using the default transform-origin value.

<style>
  .scaled {
    transform: scaleX(2);
  }
</style>

<img src="/pix/samples/9s.jpg" alt="Sample image">
<img class="scaled" src="/pix/samples/9s.jpg" alt="Sample image">

Official Syntax

The official syntax of the scaleX() function is as follows:

Possible Values

The scaleX() function accepts number parameters that define the scaling vector for the scale operation.

A number is either an integer, or zero or more decimal digits followed by a dot (.) followed by one or more decimal digits and optionally an exponent composed of e or E and an integer.

CSS Specifications

The scaleX() function is defined in CSS Transforms Module Level 1 (W3C Working Draft)

Browser Support