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Method · Updated

How we test Live Photo wallpapers

All findings on this site come from one iPhone 14 Pro Max running iOS 26, tested between June and October 2026 while building the Lockimate app. A finding counts as tested only if a file was set as the lock screen wallpaper on that phone and the result was observed on the lock screen. Everything else is labelled as coming from Apple's documentation or from App Store listings.

The test files

Most tests use Live Photo files we built for the purpose, each changing one thing at a time against a file that works: a re-encoded video track, a longer or shorter clip, a different frame rate, the key photo moved, a metadata track removed. Each file goes onto the phone the way a normal Live Photo does, through the Photos library, and gets tried as a wallpaper. When iOS refuses a file, the wallpaper editor shows "Motion not available" and the photo can only be set as a still.

Measuring what the lock screen plays

A Live Photo wallpaper can't be inspected from the outside; iOS decides at wake time which part of the clip to show. To read it, we filmed a millisecond counter as a normal camera Live Photo, set it as the wallpaper and read which counter values appear when the phone wakes. Moving the key photo in the Photos app and repeating the wake shows how the played part follows the key photo. For our own app's files, numbered frames do the same job. Results are on How long a live wallpaper plays.

Reading the file itself

File structure (the paired photo and video, the shared content identifier, the still-image-time and metadata tracks) is read with ffprobe, MP4Box and the two browser tools on this site (they need the HEIC and MOV files copied from a Mac), the Live Photo check and the Live Photo inspector. The check's motion comparison is calibrated on 13 Lockimate wallpapers that iOS accepted.

What we haven't tested

  • Other iPhone models. Apple says Live Photo wallpapers need iOS 17 or later; we have only verified one phone.
  • iOS 17 and iOS 18. Behaviour may differ there.
  • iPad.
  • The on-screen duration of the wake animation. We measured which frames play, not how long iOS takes to show them.
  • Other apps' output, unless a page says it was tried on the phone.

If your phone behaves differently from what a page says, that is useful to us. The contact address is on the About page.