resize background image in css code example

Example 1: how to scale a bg image acc to size of div

/* One way */
background-size: cover;

/* Other option */
background-size: contain;

Example 2: how to change the width of a background image in css

#example1 {		/* Example1 has an auto background size */
  background: url(mountain.jpg);
  background-repeat: no-repeat;
  background-size: auto;
}

#example2 {		/* Example2 has an fixed background size */
  background: url(mountain.jpg);
  background-repeat: no-repeat;
  background-size: 300px 100px;
}