Guide
What Apple's built-in Duplicates album misses
The Duplicates album in Photos is genuinely useful, and also narrower than most people expect. Here's exactly what it does and doesn't catch.
How the Duplicates album actually works
Open Photos, tap Collections, tap Utilities, then tap Duplicates. iOS looks for photos and videos that are exact copies of each other and groups them there. Tap Merge on a set to keep the highest-quality version with its combined captions, keywords, and favorite status; the rest move to Recently Deleted. Scanning happens in the background and can take a while to catch up on newly added photos, so it's worth checking back after your phone has spent some time charging.
What it catches
True exact copies: the same file saved twice, a photo duplicated by an import or an AirDrop, that kind of thing. If two files are genuinely identical, the Duplicates album is a fast, free, built-in way to find and merge them.
What it misses
Almost everything that looks like a duplicate to a person but isn't an exact, identical copy. That includes burst shots taken a fraction of a second apart, a handful of reshoots of the same scene, an edited photo next to its original, and the screenshots that pile up in every camera roll. None of those are "duplicates" by Apple's definition, so none of them show up here, no matter how many near-identical versions you're holding onto.
If the Duplicates album doesn't appear at all
That's expected, not broken. The Duplicates collection only shows up when Photos has found at least one set of exact matches. A library with no exact duplicates, only near-identical ones, won't show the album at all, which is a common source of confusion for people expecting it to handle every kind of clutter.
Catching what's left
Cleanup Today groups duplicates, reshoots, and repeat screenshots together by the day they were taken, so you can compare near-identical shots side by side and decide what to keep, covering the gap Apple's exact-match tool leaves behind.