Stacks Support

What do I need to use Stacks?

An iPhone running iOS 27 or later, and access to your photo library. There’s no account to create and nothing to sign in to.

Why does Stacks need access to my photos?

To find moments, Stacks looks at the photos in your library and details such as when and where each photo was taken. All of this happens on your iPhone. With Full Access, Stacks can look through your whole library. With Limited Access, Stacks only sees the photos you’ve chosen and finds moments among those photos. You can change access at any time in the Settings app, under Privacy & Security → Photos.

How does Stacks choose the best photo?

Stacks scores every photo in a moment. Open eyes, smiles, faces turned toward the camera and a sharp subject raise the score. Closed eyes, blur and haze lower it. A cat or dog looking at the camera counts too. The photo Stacks picks is marked Best, and you can tap Best to see what Stacks found. If you prefer another photo, make that photo the cover photo before you stack.

Why weren’t some of my photos grouped?

Stacks only groups photos taken within a few seconds of each other that look alike and were taken in the same place. When a new person joins the frame, a new moment starts.

Photos of a document group only when they show the same page. The front and back of a card stay apart. The clearest copy goes first.

Some photos are always left out: videos, screenshots, photos that are already bursts, and files Stacks can’t copy without losing something, such as RAW photos. Favorites and photos in your albums are left out unless you turn on those options in Stacks’ Settings, under Also Stack.

What does the small cloud mean?

The cloud marks a photo that’s kept only in iCloud, not on your iPhone, which is common with Optimize iPhone Storage. A moment shows the cloud if any photo in the moment has one.

Stacks first judges those photos from the small preview on your iPhone, and says when faces are too small to judge rather than guess. Stacks looks again at the sharper copy whenever you view the photo.

Will Stacks delete my photos?

Only the ones you choose, and only after you confirm. Swiping left just marks a photo; nothing is deleted until you choose to delete and approve iOS’s own confirmation. Deleted photos stay in Recently Deleted for 30 days.

In Clean Up, photos you swipe away wait in To Delete until you delete them, and iOS asks first.

When you stack a moment, Stacks makes the stack first and checks every copy. Only then does Stacks ask iOS to remove the separate originals, which are already inside the stack.

Keep Best Photo Only, under Select on the Unstacked tab, keeps each selected moment’s cover photo and deletes the rest, but only after a page that shows exactly which photos will go, and iOS’s own confirmation.

Delete All, under Select → More, deletes every photo in the selected moments except favorites and photos in your albums. A page shows each photo first, then iOS asks for confirmation.

What is Clean Up?

Clean Up is the third tab. It puts screenshots, documents, blurry photos, duplicates and other photos you may not need into piles, one for each kind. Swipe through a pile one photo at a time, or tap Select to keep or delete whole piles. Photos you keep go to Kept, so Clean Up doesn’t show them again. Photos you swipe away wait in To Delete until you tap Delete, and iOS asks before anything is deleted. Deleted photos stay in Recently Deleted for 30 days.

Where do the other photos go when I stack a moment?

Into a burst in Apple Photos. Your library shows the cover photo, and the rest are inside the burst: open the burst in Photos to see every photo. Dates, places, favorites, captions, keywords, ratings, albums and Live Photos carry over.

Two things don’t carry over: names you’ve given to people in Photos, and the date each photo was added to your library, which becomes the day you stacked the photo.

How do I undo a stack?

Open the Stacked tab, choose the stack and tap Unstack. Stacks restores the separate photos with the original dates, checks every photo, and then asks iOS to remove the burst. Whenever possible, each photo comes back identical to the original. To undo several stacks at once, tap Select on the Stacked tab.

I said no when iOS asked to delete. What now?

Nothing was deleted. Stacks explains what happened and offers Try Again. If you said no while stacking, the stack was still made, so for now you have both the stack and the separate photos. When you’re ready, open the stack in the Stacked tab and tap Remove Separate Photos, and iOS will ask again. If you said no while unstacking, the button is Remove Stack.

Why is Stacks downloading photos from iCloud?

Stacking works with the full original of each photo. If an original is only in iCloud, iOS downloads the original first, unchanged, and Stacks shows the download’s progress. Scanning never downloads anything, and deleting never needs a download.

What happens to my stacks if I delete Stacks?

Your stacks stay in Apple Photos as ordinary bursts. The record Stacks uses to undo a stack is kept in the app, though, and deleting the app removes that record. If you might want to unstack something later, unstack before you delete Stacks.

Does Stacks upload my photos?

No. Stacks analyzes your photos on your iPhone with Apple’s built-in tools and never connects to the internet. There’s no account, no server, no ads and no analytics.

If you use iCloud Photos, iOS may download a photo from iCloud when Stacks needs a sharper copy or an original, just as iOS does for the Photos app. Read the full privacy policy.