animation-duration

Defines how long an animation should take to complete.

animation-duration: <value>;

where <value> can be one of the following:

• Seconds: 2s
• Milliseconds: 200ms

Note: If not provided, an animation will not occur because the default value is 0s.

Change color of box from blue to white over a duration of 2 seconds:

div {
  height: 200px;
  width: 200px;
  background-color: blue;
  animation-name: disappear;
  animation-duration: 2s;
}

@keyframes disappear {
  from {
    background-color: blue;
  }
  to {
    background-color: white;
  }
}

Provide a second duration value to determine the duration of an additional animation:

div {
  height: 200px;
  width: 200px;
  background-color: blue;
  animation-name: fadeoutfadein, slideleft;
  animation-duration: 4s, 5000ms;
}

@keyframes fadeoutfadein {
  0% {
    background-color: blue;
  }
  50% {
    background-color: white;
  }
  100% {
    background-color: blue;
  }
}

@keyframes slideleft {
  from {
    margin-left: 100%;
  }

  to {
    margin-left: 0%;
  }
}