CSS Transitions

CSS transitions allows you to change property values smoothly, over a given duration.

In this chapter you will learn about the following properties:

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

How to Use CSS Transitions?

To create a transition effect, you must specify two things:

• the CSS property you want to add an effect to
• the duration of the effect

Note: If the duration part is not specified, the transition will have no effect, because the default value is 0.

The following example shows a 100px * 100px red <div> element. The <div> element has also specified a transition effect for the width property, with a duration of 2 seconds:

div {
  width: 100px;
  height: 100px;
  background: red;
  transition: width 2s;
}

div:hover {
  width: 300px;
}

Change Several Property Values

The following example adds a transition effect for both the width and height property, with a duration of 2 seconds for the width and 4 seconds for the height:

div {
  transition: width 2s, height 4s;
}

Specify the Speed Curve of the Transition

The transition-timing-function property specifies the speed curve of the transition effect.

The transition-timing-function property can have the following values:

• ease - specifies a transition effect with a slow start, then fast, then end slowly (this is default)
• linear - specifies a transition effect with the same speed from start to end
• ease-in - specifies a transition effect with a slow start
• ease-out - specifies a transition effect with a slow end
• ease-in-out - specifies a transition effect with a slow start and end
• cubic-bezier(n,n,n,n) - lets you define your own values in a cubic-bezier function

The following example shows some of the different speed curves that can be used:

Delay the Transition Effect

The transition-delay property specifies a delay (in seconds) for the transition effect.

The following example has a 1 second delay before starting:

div {
  transition-delay: 1s;
}

CSS Transition Properties

The following table lists all the CSS transition properties:

Property	Description
transition	A shorthand property for setting the four transition properties into a single property
transition-delay	Specifies a delay (in seconds) for the transition effect
transition-duration	Specifies how many seconds or milliseconds a transition effect takes to complete
transition-property	Specifies the name of the CSS property the transition effect is for
transition-timing-function	Specifies the speed curve of the transition effect