Video is one of the hardest file types to handle well. Streaming platforms, editors and upload services all need to survive damaged video. Here is how to create test files.
How video files are organized
An MP4 or MOV file is built from boxes (also called atoms). Two matter most: ftyp (identifies the file) and moov (the index describing the video and audio). If moov is missing or damaged, players often cannot play the video even when the picture data is intact. AVI files use an index chunk with a similar role.
Method 1: Online video corrupter
- Visit CorruptAnyFile.
- Upload your MP4, AVI or MOV file.
- Click Corrupt My File.
- Download the result.
The tool supports MP4, AVI, MOV, MP3 and WAV. Large files may take longer to upload.
Method 2: Truncate the video
head -c 5000000 movie.mp4 > broken.mp4
This keeps only the first 5 MB. Many MP4 files store the moov box at the end, so truncation often makes them unplayable. Some players can still play the partial video, which is a useful result to test too.
Method 3: Damage the header
Using a hex editor, change the ftyp text near the start of the file to zeros on a copy. Players will not recognize the format.
Method 4: Overwrite data in the middle
Damaging the middle often produces a different effect: the video plays, then freezes, shows green blocks or skips. This simulates a damaged storage device and is great for testing players and transcoders.
What different players do
| Player | Typical result |
|---|---|
| VLC | Tries to play and may offer to rebuild the index |
| Windows Media Player | Error message |
| Browser | Fails to load |
| FFmpeg | Prints errors but may still decode part of it |
What to test
- Does your upload service reject or queue the file?
- Does the transcoder fail cleanly or loop forever?
- Does the user get a helpful message?
If you want to repair a damaged video instead, see how to fix a corrupted file. Related: corrupt an image and how to corrupt a file.
FAQ
How do I corrupt an MP4? Upload it to CorruptAnyFile, or truncate it.
Can VLC play a corrupted video? Sometimes, partially.
Does it support audio? Yes, MP3 and WAV.