A/B Test example

Showing how to use Google Analytics and Content Experiments to do A/B Testing

HTML

<script src="//www.google-analytics.com/cx/api.js?experiment=107455202-2"></script>
<script>
    var param = window.location.search.split('var='),
        id = param[1] ? param[1] : cxApi.chooseVariation(),
        html = document.getElementsByTagName('html')[0];
    html.className = 'var' + id;
    console.log(param[1] ? 'url' : 'auto', id);
</script>

<div class="a">
    <img src="https://images-na.ssl-images-amazon.com/images/G/01/img15/pet-products/small-tiles/30423_pets-products_january-site-flip_3-cathealth_short-tile_592x304._CB286975940_.jpg" alt="" />
</div>
<div class="b">
    <img src="http://r.ddmcdn.com/s_f/o_1/cx_633/cy_0/cw_1725/ch_1725/w_720/APL/uploads/2014/11/too-cute-doggone-it-video-playlist.jpg" alt="" />
</div>

<script>
    (function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){
    (i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),
    m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)
})(window,document,'script','//www.google-analytics.com/analytics.js','ga');
ga('create', 'UA-18356538-5', 'auto');
ga('send', 'pageview');
</script>

CSS

body,
h1 {
    margin: 0;
}

.b {
    display: none;
}

.var1 .a {
    display: none;
}

.var1 .b {
    display: block;
}

.a img,
.b img {
    width: 100%;
}