What is a motion photo? Still image plus a short clip

How is a motion photo built?

Google's Motion Photo format 1.0 describes the file as a primary still image with a secondary video file appended to it. XMP metadata inside the image flags it with a Camera:MotionPhoto value of 1 and lists the length of each part, so a gallery knows where the photo ends and the video begins.

Apps that do not understand the format simply show the still image, which is why the file still opens anywhere.

Google's spec also allows a higher-resolution secondary video track and a metadata track, which camera apps can use to suggest a better frame than the one you shot.

Why do motion photos use more space?

The clip is real video, so it adds megabytes to every shot. A camera roll where motion photos are switched on by default can grow much faster than expected, with no visible sign in the thumbnail grid. Pixel calls the feature Top Shot and Motion; Samsung calls it Motion photo in the camera's quick settings.

• Turn the feature to Auto or Off in the camera app if you rarely play the clips.
• In Google Photos you can export the clip as a video or keep only the still.
• Backups count the full file, video included, against your cloud storage quota.

The clip covers a short span around the shutter press, so a motion photo can show someone walking into the frame or a candle being blown out.

Can you keep just the still image?

Yes. Most galleries offer an option to save a still frame or turn off motion on a single photo, which writes a plain image. After that, deleting the original motion file reclaims the video part. A cleaner that works on images treats a motion photo as a photo; it will not judge or trim the clip itself.

If your storage meter climbs fast, compare this with other common space users in phone storage full: what to do.

To find the heaviest files, open a file manager, sort the camera folder by size and look for photos far larger than their neighbours. On a phone that saves 12 MP stills, a still that weighs two or three times the usual size is very likely carrying a clip.