HealVideo

How to repair a corrupted MP4 file (free)

Most corrupted MP4 files are not ruined. The video is usually still inside; what broke is the index that tells a player where each frame is. Here is how to check, and how to repair it for free.

Why MP4 files get corrupted

An MP4 file has two parts: the video data, and an index (called the moov) that a camera or phone writes at the very end, when you press stop. If the battery dies, the card is pulled out, the app crashes or a copy is interrupted, the index is never written, or is cut off half way.

Players need the index, so they refuse to open the file, even though nearly all of the video is still there. That is why a corrupted MP4 is often the same size as a good one.

How to repair an MP4 with HealVideo

  1. Download HealVideo for your computer (it is free) and open it.
  2. Drop the broken MP4 into the window. HealVideo reads it and tells you, in plain words, what is wrong. Nothing is changed yet.
  3. If you have another video from the same camera that plays, add it. It shows HealVideo how that camera stores video, and gives the best result.
  4. Press Start repair. HealVideo saves a new, repaired copy next to a short report, and test-plays it before calling it done. Your original file is never changed.

What can be repaired

Recording cut short, index still there
HealVideo copies everything that is still readable into a new file that plays.
Index missing (“moov atom not found”), H.265 video
HealVideo finds the frames in the raw data and builds a new file. It needs a camera profile or one working clip from the same camera.
Index missing, H.264 video
Needs the free tool untrunc installed next to HealVideo, plus one working clip from the same camera.
Videos deleted from an exFAT memory card
HealVideo reads an image of the card and puts each video’s scattered pieces back in order.

Repaired files from the frame finder have video but no sound yet. Damage inside the picture itself (glitches in a file whose structure is fine) is not something HealVideo can undo.

Before you start

Work on a copy. HealVideo never writes to the original, but other tools might.

Don’t record anything new on the card a broken video came from. New recordings can overwrite what is left of it.

Related guides

Updated 2026-10-13. HealVideo is an early preview (version 0.1). Found a mistake? Tell us on GitHub.