Look at the padding and the placement of the laptop pocket. The laptop does not need to be surrounded by a lot of bulky padding, it just needs to be kept in a stiff and snug pocket. It is important that the laptop pocket holds the laptop a few inches away from the bottom of the backpack. This will prevent the laptop from hitting the floor every time the backpack is put down. Also look for a strap that will hold the laptop in the pocket.
Choose a backpack that does not have a lot of zippers. Zippers are the first thing to break on a backpack, and they add unnecessary weight. Also remember to test all the zippers before purchasing a backpack.
Find the perfect number of pockets and compartments. A backpack with too many compartments can get confusing and waste space, but a pack with too few is hard to organize. Ideally, a laptop backpack will have two main compartments, a laptop pocket, two or three smaller zipped compartments, an open front pocket, and an open side pocket for a water bottle.
Laptop backpacks vary widely in size. First figure out what you will be using the backpack for and then choose an appropriate size. To determine how efficient a backpack is compare the dimensions of the pack with the volume (the dimensions and volume should be provided on the tag).
Pick a backpack that is as light as possible. If you plan on carrying heavy things around then get a bag with a waist support strap. This strap will move the weight off the back and onto the hips.
Try the backpack on (if possible with the laptop in it) before buying it. Make sure you like how it looks and feels.
