CSS: transitions

CSS Transitions

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

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;
}

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

div {
  width: 100px;
  height: 100px;
  background: red;
  -webkit-transition: width 3s; /* Safari */
  -webkit-transition-delay: 1s; /* Safari */
  transition: width 3s;
  transition-delay: 1s;
}

div:hover {
  width: 300px;
}

Transition + Transformation

div {
  width: 100px;
  height: 100px;
  background: red;
  -webkit-transition: width 2s, height 2s, -webkit-transform 2s; /* Safari */
  transition: width 2s, height 2s, transform 2s;
}

div:hover {
  width: 300px;
  height: 300px;
  -webkit-transform: rotate(180deg); /* Safari */
  transform: rotate(180deg);
}

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

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