Copy canvas
HTML
<canvas id="c1"></canvas>
<canvas id="c2"></canvas>
CSS
#c1 {
background-color: red;
}
#c2 {
background-color: blue;
}
JavaScript
var c1 = document.getElementById('c1');
var c1Context = c1.getContext('2d');
var c2 = document.getElementById('c2');
var c2Context = c2.getContext('2d');
c1Context.fillRect(0, 0, 50, 50);
c2Context.drawImage(c1, 10, 10);