Do hidden photos sync to iCloud?

If you use iCloud Photos, yes. Apple says photos you hide on one device are hidden on your other devices too, so hiding travels with the photo. Hiding changes where a photo appears in the Photos app, not whether it is part of your iCloud Photos library.

Why

Hiding a photo on iPhone moves it into the Hidden album. Apple describes it as a place to keep photos out of your Library and other albums, and says that with iCloud Photos on the hidden state follows you to your other devices. Apple's page on the Hidden album does not say how hiding behaves when iCloud Photos is off, so do not assume. Apple also says that deleting a photo on one device deletes it everywhere you use iCloud Photos, which matters if you plan to remove an original after moving it elsewhere.

What to do

  1. Find out whether iCloud Photos is on. On iPhone, Apple's instructions place it under Settings, your name, iCloud, Photos.
  2. Decide whether you want that photo in iCloud at all. If you do not, do not rely on the Hidden album.
  3. For photos you want off the library, take them with a private camera inside a vault app or import them into one, then delete the original from Photos. Apple keeps deleted items in Recently Deleted for up to 30 days, so remove them there too if you need them gone sooner.
  4. Check your other devices to confirm that the photo is gone.

A copy that lived in iCloud Photos, or on another device, is a separate thing to delete.

What this does not cover

It does not cover who can read iCloud data; see can Apple see hidden photos. StrongRoom's own limits are on the limits page.

Frequently asked questions

Does the Hidden album encrypt my photos?

Apple describes it as a locked album that needs authentication to open. It does not describe it as a separate encrypted store.

Do photos taken in StrongRoom reach my library?

No. Photos taken with the private camera stay in the Vault and never reach your photo library.

Sources

StrongRoom is a free iPhone app, coming to the App Store.

Free for iPhone. Pro is optional. What Pro changes.

Coming to the App Store. See what version 1.0 includes.