What actually fills up an iPhone and how to clear it: duplicate photos, large videos and app caches.
Three things take up most of the space on an iPhone: video, duplicate photos and app caches. A minute of 4K 60 fps video is roughly 400 MB, so a handful of holiday clips runs into several gigabytes. Duplicates accumulate on their own — burst shots, images sent and saved back, repeated screenshots of the same screen. The built-in Photos app surfaces exact copies only and skips near-identical frames taken seconds apart. iOS clears app caches by itself, but it waits until storage is nearly gone. You can work through all of it by hand in Settings → General → iPhone Storage, though on a library of several thousand shots that takes hours. PhotoGO AI scans the library on the device and groups similar frames, leaving the decision to you.
Guides on iPhone storage are on the way.
