You need to do something like this:
/*************************************************************************************
by forcing `height: 100%` in the html and body tag will make sure there are no white areas in vicinity (this is optional though, use it only if you need it)
*************************************************************************************/
html,
body{
height: 100%;
}
/*************************************************************************************
by using `background-size: cover;`, you will make sure the image will cover everything
*************************************************************************************/
body{
background-size: cover;
background-repeat: no-repeat;
background-position: center center;
background-image: url("your_image.jpg");
}
Also, consider using -moz-
, and -webit-
prefixes to make sure it works in older browser versions of webkit and gecko based browsers.