An Animation in CSS: When Things Start to Move

The first step in using animation in CSS is the transition property. When predefined transitions are not enough or just not suitable, there is CSS animation.

Note: No JavaScript is used in this post!

The animation property has 2 parts: keyframes and animation property. Keyframes define stages and styles of the animation and animation property assign keyframes to the element and specify how the animation will run out on the defined element.

Keyframes

With defining keyframes you actually set steps for your animation. The syntax for this part of the animation is word @keframes followed with animation name followed by keyframe selectors and its style.

@keyframes animation-name{    0%{CSS}    50%{CSS}    100%{CSS}}

An animation is created by gradually changing from one to another style set by keyframe selectors. These selectors can have value 0%-100% (or words “from” and “to” which stand for 0% and 100%). I believe it is perfectly clear that 0% presents the beginning of the animation and 100% the end.

Properties you can animate are not infinite, so there is a list of them.

Now, the most shocking thing about the @keyframes option: !important in CSS inside of the keyframes does not only make your code important but it also ignores the whole code line...! What a shock!

Animation Property

Once the keyframes are defined you better make sure that work pays off and use them. Inside of the selector you want to animate add animation property. This property is shorthand for eight animation properties.

animation=animation-nameanimation-durationanimation-timing-functionanimation-delayanimation-iteration-countanimation-directionanimation-fill-modeanimation-play-state

Main properties to add are animation-name and animation-duration. Without animation-name you can't link animation to keyframes and without animation-duration duration will be set to 0 and again, there is no animation.

Other properties are used for better defining animation. The Animation-timing-function specifies the speed curve of the animation. It can be defined with pre-defined values (linear, ease, ease-in, ease-out, ease-in-out) or custom defined by steps or cubic-bezier values.

Animation-delay property works pretty much the same as transition一it defines the start of the animation.

By default, the animation will be played one time. With animation-iteration-coun you can change this to any number or define it as infinite.

Animation-direction property specifies animation cycle一whether it will be played forwards, backward or in alternate cycles. Options that define those states are normal, reverse, alternate (forward then backward) and alternate-reverse (backward then forward).

Animation-fill-mode property defines a style of the element when the animation ends or before it started. The default state is none and in this state animation will not apply any styles to the animated element. The option both will set the first keyframe value to the element until it starts, and last keyframe value after it ends. Options forwards and backwards defined separated options from both.

And finally, with animation-play-state you can pause the animation and play it again. So, it has 2 options, running (which is default) and paused.

Even animation property is shorthand for all listed options, it is common to use it just for animation-name and animation-duration and other properties list separated.

animation: icon-animation 2s;animation-timing-function:ease;animation-delay: 5s;animation-iteration-count:infinite;animation-direction:normal;animation-fill-mode:both;animation-play-state:running;

Just for the record, it is possible to add more than one animation to the element.

And just a short note about prefixes: with all animation properties and keyframes you should use -webkit-. For few specific known issues check CanIUse.

Examples

The animation to itself is not really a thing that has a specific purpose in the design. On the other hand, it can be used wherever, and it will always add a value. I will say that specific animation (defined with this property) is used on the special effects the most, and animation defined with the transition is used on more common elements like hover and other states.

Also, some effects on hover effect, even just a line with unusual behavior is defined with animation property.

So, if you need to add “that something” to your already finished design, you add a special effect to the background or on some specific elements (loader, scroll, hover…).

If you are looking for a nice blog with a much nicer post with the nicest CSS animation examples be sure to check the one on Creative Bloq.

Also, be sure to check Animista for a lot of predefined animation you can easily use.

Epilogue

The animation property is, in my opinion, one of the highest CSS properties so if not because the wow effect, you need it to your “master CSS” goal. If you are interested in UX (if not you maybe should be), check out a very nice text about animation from the Invision App team.

Stay tuned for more CSS related posts!

Originally published at kolosek.com on June 12, 2018.

An Animation in CSS: When Things Start to Move was originally published in Hacker Noon on Medium, where people are continuing the conversation by highlighting and responding to this story.