How to sort through thousands of photos on iPhone, one month at a time

A camera roll of twenty thousand photos is hard to sort because it has no natural stopping point. You scroll, delete a few, get interrupted, and later cannot remember where you stopped. Most attempts end after the first evening.

Splitting the library into months solves that. Each month is a small task you can finish, photos appear next to the rest of the trip or week they belong to, and choosing is easier when the alternatives sit side by side.

Rules that keep a review quick

• One decision per photo. Keep or delete. Do not stop to edit or file photos into albums; do that later with what you kept.
• Mark favourites in the Photos app. Pruna shows a favourite badge on each card, and favourites are never preselected in its cleanup categories.
• When in doubt, keep. A photo you hesitate over can wait for a later pass. Deleting is the only step that needs certainty.
• Mark now, delete at the end. Deleting in one batch at the end gives you a last look at everything before it leaves the library.
• Finish a month before you stop. One month done beats three half-done, and the next session starts from a clean line.
• Leave copies to the categories. Exact duplicates and bursts are faster to handle in Pruna's Duplicates and Similar photos lists. Month by month is for the photos only you can judge.

Doing it in the Photos app

The Photos app groups the library by date, and you can select several photos and delete them together. What it cannot do is remember which photos you have already looked at. After a break you are back to scrolling and guessing where you stopped, and every deletion happens on the spot rather than after a final review.

Going month by month with Swipe in Pruna

1. Open Pruna, allow access to your photos and let the first scan finish. Swipe covers everything the scan saw, photos and videos alike, not only the items in the cleanup categories.
2. Open the Swipe tab. The newest month comes first, with its newest photo on top. The month picker jumps to any other month and shows how many items are left in each; photos without a date have their own Undated group.
3. Each card shows when the photo was taken and its size, plus the length of a video. Swipe right to keep and left to mark for deletion, or use the buttons under the card.
4. Tap Undo to bring the last card back. Up to 50 recent decisions can be taken back.
5. Every decision is saved as soon as the card leaves the screen, so you can close the app and continue later from the same card. When a month is done, Pruna offers the next one.
6. When you are ready, tap Review next to the count of items marked for deletion. Everything is ticked; untick anything you want to keep after all. Confirm, and iOS asks once before the photos move to Recently Deleted.

Limits worth knowing

• Swiping left only marks a photo. Nothing leaves the library until you confirm the review list.
• Deleted photos stay in Recently Deleted for 30 days and can be recovered there. They keep using space until that album is emptied.
• With iCloud Photos, deleting a photo removes it from every device signed in to the same Apple Account.
• Sizes of plain photos are estimates, marked ≈, until the files of the open month have been read.
• Swiping and saving your decisions are free. Deleting the marked photos is part of Pruna Pro, whose price is shown in the App Store before you subscribe.