If the property has a value different than none, a stacking context will be created. In that case, the element will act as a containing block for any position: fixed; or position: absolute; elements that it contains.

/* Keyword values */
transform: none;

/* Function values */
transform: matrix(1, 2, 3, 4, 5, 6);
transform: matrix3d(1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1);
transform: perspective(17px);
transform: rotate(0.5turn);
transform: rotate3d(1, 2, 3, 10deg);
transform: rotateX(10deg);
transform: rotateY(10deg);
transform: rotateZ(10deg);
transform: translate(12px, 50%);
transform: translate3d(12px, 50%, 3em);
transform: translateX(2em);
transform: translateY(3in);
transform: translateZ(2px);
transform: scale(2, 0.5);
transform: scale3d(2.5, 1.2, 0.3);
transform: scaleX(2);
transform: scaleY(0.5);
transform: scaleZ(0.3);
transform: skew(30deg, 20deg);
transform: skewX(30deg);
transform: skewY(1.07rad);

/* Multiple function values */
transform: translateX(10px) rotate(10deg) translateY(5px);
transform: perspective(500px) translate(10px, 0, 20px) rotateY(3deg);

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

The transform property may be specified as either the keyword value none or as one or more <transform-function> values.

If perspective() is one of multiple function values, it must be listed first.

<transform-function>

One or more of the CSS transform functions to be applied. The transform functions are multiplied in order from left to right, meaning that composite transforms are effectively applied in order from right to left.

none

Specifies that no transform should be applied.

Scaling/zooming animations are problematic for accessibility, as they are a common trigger for certain types of migraine. If you need to include such animations on your website, you should provide a control to allow users to turn off animations, preferably site-wide.

Also, consider making use of the prefers-reduced-motion media feature — use it to write a media query that will turn off animations if the user has reduced animation specified in their system preferences.

Find out more:

• MDN Understanding WCAG, Guideline 2.3 explanations
• Understanding Success Criterion 2.3.3 | W3C Understanding WCAG 2.1

transform = 
  none              |
  <transform-list>  

<transform-list> = 
  <transform-function>+  

HTML

<div>Transformed element</div>

CSS

div {
  border: solid red;
  transform: translate(30px, 20px) rotate(20deg);
  width: 140px;
  height: 60px;
}

Result

The order of transform functions matters. In this example, two boxes are rotated and translated by the same values; only the transform function order is different.

HTML

<div class="original"></div>
<div class="one">1</div>
<div class="two">2</div>

CSS

.one {
  transform: translateX(200px) rotate(135deg);
}
.two {
  transform: rotate(135deg) translateX(200px);
}

Result

When an element is rotated before being translated, the translate direction is on the rotated axis. The axis as indicated with the dotted lines.

Please see Using CSS transforms and <transform-function> for more examples.

• Using CSS transforms
• <transform-function> data type with all the transform functions explained.
• Individual CSS properties: translate, rotate), and scale (there is no skew property).
• Online tool to visualize CSS Transform functions: CSS Transform Playground