How to clear duplicate photos and free up phone space

Few things are more annoying than an iPhone or Android phone telling you storage is full just as you try to film the school concert. Usually the culprit is your photo library, stuffed with burst shots, screenshots, near-identical selfies and the same picture saved three times from three different chats. The good news is that both Apple and Google have built tools to find duplicates and clear space without losing anything you care about.