Transitions enable you to define the transition between two states of an element. Different states may be defined using pseudo-classes like :hover or :active or dynamically set using JavaScript.

This property is a shorthand for the following CSS properties:

• transition-delay
• transition-duration
• transition-property
• transition-timing-function

/* Apply to 1 property */
/* property name | duration */
transition: margin-right 4s;

/* property name | duration | delay */
transition: margin-right 4s 1s;

/* property name | duration | easing function */
transition: margin-right 4s ease-in-out;

/* property name | duration | easing function | delay */
transition: margin-right 4s ease-in-out 1s;

/* Apply to 2 properties */
transition: margin-right 4s, color 1s;

/* Apply to all changed properties */
transition: all 0.5s ease-out;

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

The transition property is specified as one or more single-property transitions, separated by commas.

Each single-property transition describes the transition that should be applied to a single property (or the special values all and none). It includes:

• zero or one value representing the property to which the transition should apply. This may be any one of:
  • the keyword none
  • the keyword all
  • a <custom-ident> naming a CSS property.
• zero or one <easing-function> value representing the easing function to use
• zero, one, or two <time> values. The first value that can be parsed as a time is assigned to the transition-duration, and the second value that can be parsed as a time is assigned to transition-delay.

See how things are handled when lists of property values aren't the same length. In short, extra transition descriptions beyond the number of properties actually being animated are ignored.

transition = 
  <single-transition>#  

<single-transition> = 
  [ none | <single-transition-property> ]  ||
  <time>                                   ||
  <easing-function>                        ||
  <time>                                   

<single-transition-property> = 
  all             |
  <custom-ident>  

<easing-function> = 
  linear                          |
  <linear-easing-function>        |
  <cubic-bezier-easing-function>  |
  <step-easing-function>          

<linear-easing-function> = 
  linear( <linear-stop-list> )  

<cubic-bezier-easing-function> = 
  ease                                                |
  ease-in                                             |
  ease-out                                            |
  ease-in-out                                         |
  cubic-bezier( <number [0,1]> , <number> , <number [0,1]> , <number> )  

<step-easing-function> = 
  step-start                                |
  step-end                                  |
  steps( <integer> [, <step-position> ]? )  

<linear-stop-list> = 
  [ <linear-stop> ]#  

<step-position> = 
  jump-start  |
  jump-end    |
  jump-none   |
  jump-both   |
  start       |
  end         

<linear-stop> = 
  <number>               &&
  <linear-stop-length>?  

<linear-stop-length> = 
  <percentage>{1,2}  

This example performs a four-second font size transition with a one-second delay when the user hovers over the element.

HTML

<a class="target">Hover over me</a>

CSS

.target {
  font-size: 14px;
  transition: font-size 4s 1s;
}

.target:hover {
  font-size: 36px;
}

There are several more examples of CSS transitions included in the Using CSS transitions article.

• Using CSS transitions
• TransitionEvent