iMac Intel 21.5" Retina 4K Display 2017 Repairability Score: 3 out of 10 (10 is easiest to repair)

The CPU and RAM—two of the components you are most likely to upgrade at some point—are both modular.

The standard 2.5" SATA hard drive is fully upgradable—though you can't add a blade SSD thanks to an empty pad on the logic board.

Cutting the tape to open the iMac isn't too hard (with the right tools), but it must then be replaced to complete any repair.

Most replaceable components (like the RAM) are buried behind the logic board, meaning you'll have to take apart most of the iMac just to gain access to them.

The glass and Retina Display are fused together, increasing the cost of replacement.