Retina
<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title></title> </head> <body> <style> .g { width: 300px; height: 200px; background-image: url(g.jpg); background-size: 300px 200px; } @media only screen and (-Webkit-min-device-pixel-ratio: 1.5), only screen and (-moz-min-device-pixel-ratio: 1.5), only screen and (-o-min-device-pixel-ratio: 3/2), only screen and (min-device-pixel-ratio: 1.5) { .icon { background-image: url(g@2x.jpg); } } </style> <div class="g"></div> <script> var img = new Image() img.width = 300 img.height = 200 img.src = window.devicePixelRatio > 1 ? 'g@2x.jpg' : 'g.jpg' document.body.appendChild(img) </script> </body> </html>