CSS Transitions

CSS Transitions

CSS transitions allows you to change property values smoothly (from one value to another), over a given duration.

Example: Mouse over the element below to see a CSS transition effect:

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;
    -webkit-transition: width 2s; /* Safari */
    transition: width 2s;
}

The transition effect will start when the specified CSS property (width) changes value.

Now, let us specify a new value for the width property when a user mouses over the <div> element:

div:hover {
    width: 300px;
}

Notice that when the cursor mouses out of the element, it will gradually change back to its original style.

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 {
    -webkit-transition: width 2s, height 4s; /* Safari */
    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 the some of the different speed curves that can be used:

#div1 {transition-timing-function: linear;}
#div2 {transition-timing-function: ease;}
#div3 {transition-timing-function: ease-in;}
#div4 {transition-timing-function: ease-out;}
#div5 {transition-timing-function: ease-in-out;}

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 {
    -webkit-transition-delay: 1s; /* Safari */
    transition-delay: 1s;
}

Transition + Transformation

The following example also adds a transformation to the transition effect:

div {
    -webkit-transition: width 2s, height 2s, -webkit-transform 2s; /* Safari */
    transition: width 2s, height 2s, transform 2s;
}

More Transition Examples

The CSS transition properties can be specified one by one, like this:

div {
    transition-property: width;
    transition-duration: 2s;
    transition-timing-function: linear;
    transition-delay: 1s;
}

or by using the shorthand property transition:

div {
    transition: width 2s linear 1s;
}