Support

Need help with PhotoDiff? Most questions are answered below — and for anything else, we read and answer every email.

• How do I start? Create a subject on Home — a skincare routine, a room, a haircut — and add a before photo. Every after photo you add later is compared against it. Settings → Show app tour again replays the introduction.
• Which photos can the app see? Only the ones you pick. Photos come in through the iOS photo picker, one at a time, when you tap to add them.
• How do I line two photos up? Open a pair and use auto-align — PhotoDiff finds the face in each photo and uses the eyes as alignment points. If a photo has no clear face, match them yourself — draw a box around a part that does not change, or place two points precisely.
• Does the app recognise who is in my photos? No. It detects where a face and its eyes are so it can align the pictures. It never identifies anyone, and nothing derived from a face leaves your device.
• Why does the comparison screen turn sideways? Side by side, slider and overlay all need the width, so the comparison view is landscape by design.
• Can I hide a face before sharing? Yes — mosaic just the eyes, the whole face, or regions you draw. The mosaic is applied to what you see and to what you export.
• How do I save or share a comparison? Tap share on the comparison screen and pick a destination from the iOS share sheet — Save Image puts it in Photos. Exports carry no watermark.

PhotoDiff is a paid app bought once on the App Store. There are no in-app purchases and no subscription — every feature is included, so there is nothing to restore and nothing to cancel.

• Installing on a new iPhone or iPad: sign in with the same Apple Account, open the App Store → your profile → Apps, and download PhotoDiff. You are not charged again.
• Refunds are handled by Apple at reportaproblem.apple.com.

Your photos, alignments and comparisons are stored only on your device and are never uploaded. PhotoDiff sends pseudonymous usage analytics that never include photos or face data — see the Privacy Policy for details.

• Delete a pair: press and hold its card, then tap Delete.
• Delete a subject and all of its photos: swipe it left on Home.
• Remove everything: delete the app. Because nothing is kept on a server, that is the whole of it — and it also means we cannot recover deleted photos for you.

• Auto-align did not find a face: it needs both eyes reasonably visible. Try a less angled photo, or match the photos by hand with a box or two points.
• Lighting makes the photos look different: use the brightness adjustment on the comparison screen to even them out.
• A photo will not import: very large or unusual formats can fail. Save a copy from the Photos app first, then add the copy.
• The app will not open or behaves oddly: close it from the app switcher and reopen, and make sure you have the latest version from the App Store. If it persists, email us your device model and iOS version.

Found a bug, have a feature idea, or anything else on your mind? Email us and we'll get back to you as soon as we can. Including your device model and iOS version helps.