[Solved – 9 Answers] CSS – HTML – Stretch and scale a CSS image in the background – with CSS only

background-size: 100%;

<div id="background">
    <img src="imgwiki.jpg" class="stretch" alt="" />
</div>

#background 
{
    width: 100%; 
    height: 100%; 
    position: fixed; 
    left: 0px; 
    top: 0px; 
    z-index: -1; /* Ensure div tag stays behind content; -999 might work, too. */
}
.stretch 
{
    width:100%;
    height:100%;
}

html,body 
{
    background: url(images/bg.jpg) no-repeat center center fixed;
    -webkit-background-size: cover; /* For WebKit*/
    -moz-background-size: cover;    /* Mozilla*/
    -o-background-size: cover;      /* Opera*/
    background-size: cover;         /* Generic*/
}

background-size: 100% 100%; 

background: url('imgwiki.png') no-repeat; 
background-size: 100%;

.stretch 
{
            background: url(images/wikitechy.jpg) no-repeat center center fixed;
            -webkit-background-size: cover;
            -moz-background-size: cover;
            -o-background-size: cover;
            background-size: cover;
}

{
background-size:contain;
background-repeat: no-repeat;
}

html 
{ 
  background: url(images/wiki.jpg) no-repeat center center fixed; 
  -webkit-background-size: cover;
  -moz-background-size: cover;
  -o-background-size: cover;
  background-size: cover;
}