Reason 1: Recently Deleted is still holding them
This is the most common one. Deleted photos don’t leave your phone — they move to Recently Deleted and keep taking up space for up to 30 days. To reclaim it now, open Photos › Albums › Recently Deleted, then Select › Delete All.
Do this only when you’re sure: once you empty it, the 30-day safety net is gone.
Reason 2: you deleted lots of small files, not the heavy ones
Five hundred photos might be a couple of hundred megabytes; one 10-minute 4K video can be more than that on its own. If the bar barely moved, you cleared count, not weight.
Sort by size instead: long videos, screen recordings, and the images you saved from other apps. Kept shows each category with the gigabytes it would free, so you go after the heavy piles first.
Reason 3: “System Data” and caches
Part of your storage is System Data (formerly “Other”) — caches, logs and temporary files iOS manages itself. It grows and shrinks on its own and usually can’t be cleared directly; restarting the phone and giving it a day often trims it.
Message attachments are a sneaky one too: Settings › General › iPhone Storage › Messages lets you clear large photo and video attachments.
Reason 4: iCloud Photos is re-downloading
With Optimize iPhone Storage on, deleting a local lightweight copy may free little, and the phone can re-download originals when there’s space. iCloud Photos is storage management, not a way to permanently shrink your library.
If your library keeps growing, the durable fix is removing photos you don’t need (which syncs everywhere) — not just toggling iCloud settings.
The reliable fix, in order
First empty Recently Deleted. Then clear the heaviest items — big videos, screen recordings, saved-from-apps. Then thin out near-duplicate bursts, blurry shots and old screenshots. That sequence reclaims real space instead of nudging the bar.
Kept runs that whole sequence for you on-device, pre-judging each photo so you just confirm — and every delete is reversible for 30 days. Cleaning by hand is free.