CSS Transitions

By  on  

There are two ways to create animations with pure CSS:  CSS animations and CSS transitions.  CSS transitions provide a simple method for animation one or multiple properties from one value to another.    CSS transitions do not require @keyframes -- simply provide the desired transition properties to a selector.  CSS transitions traditionally occur upon state changes, like :hover or :focus.

A Basic CSS Transitions

Let's create a basic CSS transition of opacity (a fade in and out):

/* from */
.myElement {
	opacity: 0.5;
	transition-property: opacity;
}

/* to */
.myElement:hover {
	opacity: 1;
}

In the example above, when the element is hovered over, its opacity animates from 50% opacity to 100% opacity.  When the mouse leaves the element, its opacity animates back down to 50%.

CSS Transition Properties

Outside of simply providing a CSS property to transition, there are a number of other helpful transition properties:

  • transition-property: one or more properties, or "all", to transition
  • transition-duration: amount of time the transition should take to complete (ex: 2s or 0.5s)
  • transition-delay: delay before starting the transition
  • transition-timing-function: traditional timing curve function for the transition

These transition properties allow complete control over the simple animation.  Here's a CSS transition example using all of the properties available:

/* from */
.myElement {
	color: #333;

	transition-property: color;
	transition-duration: 1s;
	transition-delay: .2s;
	transition-timing-function: linear;
}

/* to */
.myElement:focus {
	color: #999;
}

/* shorthand: property duration timingFunc delay */
.myElement {
	transition: all 2s linear 0.3s;
}

In most cases, the default duration, delay,and timing function wont need to be changed.

Transitioning Multiple Properties

Multiple transition properties should be separated by commas:

.myElement {
	/* padding-left, opacity, height, and color here */

	transition-property: padding-left, opacity, height, color;
	transition-duration: 1s, 2s, 3s, 4s;
}

The "all" keyword can also be used to signify all properties should be transformed.  Separate transitions may also be strung together in a shorthand syntax:

.myElement {
	transition: padding-left 1s, opacity 2s, height 3s, color: 4s;
}

The property value can get quite long, but the flexibility is quite nice!

Detecting Transition End with JavaScript

If you're looking to detect transition end with JavaScript, that's quite easy:

myElement.addEventListener("transitionend", function() {

	// Do something now that the transition has ended

}, true);

The transitionend event on the node will fire once the transition has completed.

CSS Transition Examples

My blog has featured a number of CSS transition examples:

Raygun Pulse

Recent Features

  • By
    Convert XML to JSON with JavaScript

    If you follow me on Twitter, you know that I've been working on a super top secret mobile application using Appcelerator Titanium.  The experience has been great:  using JavaScript to create easy to write, easy to test, native mobile apps has been fun.  My...

  • By
    fetch API

    One of the worst kept secrets about AJAX on the web is that the underlying API for it, XMLHttpRequest, wasn't really made for what we've been using it for.  We've done well to create elegant APIs around XHR but we know we can do better.  Our effort to...

Incredible Demos

  • By
    Google Extension Effect with CSS or jQuery or MooTools JavaScript

    Both of the two great browser vendors, Google and Mozilla, have Extensions pages that utilize simple but classy animation effects to enhance the page. One of the extensions used by Google is a basic margin-top animation to switch between two panes: a graphic pane...

  • By
    Facebook-Style Modal Box Using MooTools

    In my oh-so-humble opinion, Facebook's Modal box is the best modal box around. It's lightweight, subtle, and very stylish. I've taken Facebook's imagery and CSS and combined it with MooTools' awesome functionality to duplicate the effect. The Imagery Facebook uses a funky sprite for their modal...

Discussion

Wrap your code in <pre class="{language}"></pre> tags, link to a GitHub gist, JSFiddle fiddle, or CodePen pen to embed!