How to fix a corrupted MOV file on a Mac

A corrupted MOV file almost always has a damaged or missing index (the part of the file that tells a player where every frame lives), usually because a recording or a copy stopped before the file was finished. If the video data itself is still on disk, a repair tool can rebuild that index and give you back most or all of the footage. If the data was never written, nothing can recover it, and a good tool will tell you that rather than pretend.

Check that the file is actually corrupted

A surprising number of “corrupted” MOV files are fine. MOV is a container, and the container can hold codecs that QuickTime Player does not understand. An error about compatibility, or a window that opens and shows nothing, is a different problem from real damage.

1. Select the file in Finder and press Command-I. Look at the size. A file of 0 bytes, or a few kilobytes for what should be minutes of video, has no data to repair. A file of the expected size is a good sign.
2. Open it in QuickTime Player (right-click, Open With). If QuickTime offers to convert it, let it try. That is a compatibility issue, not corruption, and the conversion usually works.
3. Try a second player. If a different player plays the file normally, the file is intact and QuickTime simply lacks the codec. See QuickTime says the file isn’t compatible for that case.
4. If every player fails, the file is the right size, and the error mentions the movie being damaged or the file being invalid, you are looking at real corruption.

Why MOV files break

MOV and MP4 share the same underlying structure (both are built on the QuickTime file format). The recorder writes the video and audio samples as it goes and then, when recording stops, writes a table called the moov atom that lists where each sample is and how long it lasts. Players need that table to do anything.

The table is written last. So anything that interrupts the recording before the end leaves a file full of perfectly good frames with no map to them:

• A camera or phone that lost power or ran out of storage mid-recording.
• A screen recording that was ended by a crash or a forced quit.
• A copy from an SD card or an external drive that was unplugged early. See File transfer interrupted.
• A download that stopped partway and was saved anyway.
• A drive with bad sectors that corrupted part of the file after it was written.

The first four cases are repairable in principle, because the frames exist and only the index is missing. The last case depends on what the bad sectors hit.

Things to try before any repair tool

These take a minute and occasionally solve the problem outright.

1. Copy the file to your Mac’s internal drive if it is on a card or an external disk, and work on the copy. Never repair in place on the card.
2. Open the local copy in QuickTime Player again. A file that was fine on the card but broken after a copy is a transfer problem, and copying again fixes it.
3. Check whether the source still has the original. Cameras and phones often keep a recoverable copy on the card, and the original in Photos on an iPhone is often intact even when the AirDropped copy is not. See iPhone video won’t play on Mac after AirDrop.
4. If you are comfortable in Terminal and have ffmpeg installed, try a remux: ffmpeg -i broken.mov -c copy remuxed.mov. This rewrites the container without touching the video data. It fixes files with minor structural faults but fails on a missing index, because ffmpeg needs the index to read the input at all.

Repair the file with Manatee

When the index is the problem, you need something that reads the raw samples from the file, works out the frame boundaries and timing from the data itself, and writes a new container around them. That is what the Repair mode in Manatee does for MOV, MP4, and the other common video formats.

1. Download Manatee and open it. The full feature set is free for 24 hours with no card or email, so you can repair the file before deciding whether to keep the app.
2. Drag the MOV onto the Manatee window, or onto the menu bar icon, or right-click it in Finder and choose Fix with Manatee.
3. Wait for the job to finish. The job list shows progress; a long 4K recording can take a few minutes because every frame is scanned.
4. Read the outcome. Manatee reports one of three results: Fixed, Partial (with a figure such as “the first eleven minutes”), or Not fixable.
5. Find the repaired copy next to the original. Manatee never modifies your original file; it always writes a new one alongside.

Everything happens on your Mac. The file is not uploaded anywhere, which matters when the footage is personal or belongs to a client.

What a partial repair means

A Partial result is not a half-done job. It means the file contained a usable run of frames up to a point and then garbage or nothing. A recording that was cut off at eleven minutes will come back as eleven minutes, and the last second or two may be trimmed because an incomplete frame cannot be decoded. Audio is sometimes recovered for a slightly different span than video when the two streams were written in separate chunks.

For a clearer picture of what these results mean in practice, read Partial recovery explained.

When it cannot be fixed

Be realistic about the limits:

• A 0-byte file, or one that is far too short for its length, never contained the footage. No tool can help. See Video file is 0 bytes or shows the wrong length.
• A file that was overwritten or deleted is a data recovery problem, not a repair problem. Manatee is not an undelete tool.
• Encrypted or DRM-protected files will not open regardless of their condition.
• A drive that is failing should be backed up first. Repairing files on a dying disk is a race you will lose.

Questions

Will the repaired MOV lose quality? No. Repair rebuilds the container around the existing compressed frames; it does not re-encode them. The picture and sound are bit for bit what the camera wrote. Only frames that were incomplete or unreadable are dropped.

Can I repair a MOV file without installing anything? Only in the mild cases. QuickTime Player will convert files it considers incompatible, and a clean copy from the source fixes transfer damage. A missing index needs a tool that reconstructs it, whether that is ffmpeg in Terminal (which handles some cases) or Manatee.

My MOV plays but the picture freezes partway through. Is that corruption? Usually yes, a localized one. A block of damaged data in the middle of the file stops the decoder at that point. Repair tools can often step over the damaged region and resume, so you lose a few seconds rather than the rest of the video.

Does it matter whether the file came from an iPhone, a camera, or a screen recording? Not for the repair itself. All of them produce the same container structure. The source matters for one thing: whether an intact original still exists somewhere you can copy from, which is always the better fix.