CSS3 background image transition

Question

You can transition background-image. Use the CSS below on the img element:

-webkit-transition: background-image 0.2s ease-in-out;
transition: background-image 0.2s ease-in-out;

This is supported natively by Chrome, Opera and Safari. Firefox hasn't implemented it yet (bugzil.la). Not sure about IE.

The solution (that I found by myself) is a ninja trick, I can offer you two ways:

first you need to make a "container" for the <img>, it will contain normal and hover states at the same time:

<div class="images-container">
    <img src="http://lorempixel.com/400/200/animals/9/">
    <img src="http://lorempixel.com/400/200/animals/10/">
</div>

• with CSS3 selectors http://jsfiddle.net/eD2zL/1/ (if you use this one, "normal" state will be first child your container, or change the nth-child() order)

• CSS2 solution http://jsfiddle.net/eD2zL/2/ (differences between are just a few selectors)

Basically, you need to hide "normal" state and show their "hover" when you hover it

and that's it, I hope somebody find it useful.

I've figured out a solution that worked for me...

If you have a list item (or div) containing only the link, and let's say this is for social links on your page to facebook, twitter, ect. and you're using a sprite image you can do this:

<li id="facebook"><a href="facebook.com"></a></li>

Make the "li"s background your button image

#facebook {
   width:30px;
   height:30px;
   background:url(images/social) no-repeat 0px 0px;
}

Then make the link's background image the hover state of the button. Also add the opacity attribute to this and set it to 0.

#facebook a {
   display:inline-block;
   background:url(images/social) no-repeat 0px -30px;
   opacity:0;
}

Now all you need is "opacity" under "a:hover" and set this to 1.

#facebook a:hover {
   opacity:1;
}

Add the opacity transition attributes for each browser to "a" and "a:hover" so the the final css will look something like this:

#facebook {
   width:30px;
   height:30px;
   background:url(images/social) no-repeat 0px 0px;
}
#facebook a {
   display:inline-block;
   background:url(images/social) no-repeat 0px -30px;
   opacity:0;
   -webkit-transition: opacity 200ms linear;
   -moz-transition: opacity 200ms linear;
   -o-transition: opacity 200ms linear;
   -ms-transition: opacity 200ms linear;
   transition: opacity 200ms linear;
}
#facebook a:hover {
   opacity:1;
   -webkit-transition: opacity 200ms linear;
   -moz-transition: opacity 200ms linear;
   -o-transition: opacity 200ms linear;
   -ms-transition: opacity 200ms linear;
   transition: opacity 200ms linear;
}

If I explained it correctly that should let you have a fading background image button, hope it helps at least!

Unfortunately you can't use transition on background-image, see the w3c list of animatable properties.

You may want to do some tricks with background-position.

You can use pseudo element to get the effect you want like I did in that Fiddle.

CSS:

.title a {
    display: block;
    width: 340px;
    height: 338px;
    color: black;
    position: relative;
}
.title a:after {
    background: url(https://lh3.googleusercontent.com/-p1nr1fkWKUo/T0zUp5CLO3I/AAAAAAAAAWg/jDiQ0cUBuKA/s800/red-pattern.png) repeat;
    content: "";
    opacity: 0;
    width: inherit;
    height: inherit;
    position: absolute;
    top: 0;
    left: 0;
    /* TRANSISITION */
    transition: opacity 1s ease-in-out;
    -webkit-transition: opacity 1s ease-in-out;
    -moz-transition: opacity 1s ease-in-out;
    -o-transition: opacity 1s ease-in-out;
}
.title a:hover:after{   
    opacity: 1;
}

HTML:

<div class="title">
    <a href="#">HYPERLINK</a>
</div>