Very Large Devices
Your device is larger than 1200px wide

Large Devices, Wide Screens
Your device is less than 1200px wide

Medium Devices, Desktops
Your device is less than 992px wide

Small Devices, Tablets
Your device is less than 768px wide

Extra Small Devices, Phones
Your device is less than 480px wide

Custom, iPhone Retina
Your device is less than 320px wide