Deleting duplicates: Android 1.5.3 and iPhone 1.0.1 compared

This post compares what deleting duplicates does in DeDup 1.5.3 on Android and DeDup 1.0.1 on iPhone. Both apps hand the final removal to the operating system, and both ask you to sign in before you can remove anything. The steps in between are different, and so is what happens to the file afterwards.

Android, DeDup 1.5.3: delete, then confirm in Android

• In the photo scanner you tick the copies you want gone, then press the Delete button, which shows the count and size of your selection. You can also delete a single photo from its card.
• "Auto Clear" is the bulk option. Its dialog says it keeps one copy from each group and deletes the rest, and it adds: "Visual similarity detection can occasionally make mistakes. Proceed?" In the code, the copy kept is the first item in each group.
• Next, Android shows its own delete prompt. On Android 11 and newer, DeDup requests it through the system's delete request, so the system lists the files itself. If you decline, nothing is deleted.
• The same path is used by the video scanner, Smart Cleanup, the Files tab cleanup, the dashboard search and Agent Mode.
• The deletion is permanent. DeDup has a Trash screen, but in 1.5.3 nothing in the scanners sends files to it.
• On Android 10 the system asks for consent file by file. On older versions the code deletes directly under the storage permission you granted.

iPhone, DeDup 1.0.1: Move to Trash, then delete from Photos

• In a scanner review screen, DeDup pre-selects everything except the copy it ranks as the best in each group. You can change the selection.
• The button is "Move to Trash". There's no system prompt at this step and nothing is deleted yet. The items are hidden from DeDup's results, and they stay in the Photos app.
• To remove them, open Trash and choose Delete or Empty Trash. DeDup asks "Delete ... permanently?" and then iOS shows its own confirmation. If you decline, the items stay in Trash.
• DeDup's own text says iOS keeps deleted items in Recently Deleted for 30 more days. The space comes back once that album is emptied in Photos.
• Trash can also delete on its own after a retention period. The setting's footer says iOS asks you to confirm before anything is deleted.

What's the same

• The operating system carries out the deletion, and you get a system-level confirmation.
• Guests can scan and review. Deleting needs a signed-in account on both.
• Before a photo leaves the library, the system asks you. That includes Trash's automatic clearing on iPhone.

What differs

• Steps: one delete action plus a system prompt on Android. Two stages on iPhone: Move to Trash, then delete from Photos.
• Recovery inside DeDup: none on Android 1.5.3 once the system prompt is accepted. On iPhone, items sit in Trash until you restore or delete them, or until the retention period ends.
• Where a removed item goes: on iPhone, to Recently Deleted, according to DeDup's own text. On Android, the code treats it as permanent.

Scope of this post

Checked against: DeDup 1.5.3 source code (Android) and DeDup 1.0.1 source code (iPhone).

Not tested on a device: how the Android and iOS prompts look, the Android 10 and older paths, and how Recently Deleted behaves on a real iPhone. The Recently Deleted details come from DeDup's own on-screen text, not from running the app.