VLC and those other tools are great suggestions, no doubt. But have you tried using a hex editor? Sometimes the corruption is just a few misplaced bytes, and if you can identify simple error patterns with a hex editor, you might manually correct them, especially if it’s a header issue. It’s more advanced and nitty-gritty, but worth a shot if you’re comfortable with a bit more technical tinkering.
Another option is the FFmpeg command line. It can remux the video file which occasionally fixes corruption issues. A simple command like:
ffmpeg -i corrupted.mp4 -c copy fixed.mp4
This won’t re-encode, so it just copies the streams, and sometimes the new file’s structure is correct enough to save it.
As for the Clever Online Video Repair tool that was mentioned, if the file size is a concern, or you’re worried about the privacy of sensitive footage, then the likes of local tools like Stellar or Wondershare are valid. They’re more protected since you’re doing everything on your machine.
Finally, and not to contradict but to complement, I rarely trust just one solution. Try running the corrupted file through multiple tools in sequence. Start with VLC’s repair, then run it through an online tool like https://repair.cleverfiles.com’ – Free Online Video Repair Tool, and finally, if there’s still any semblance of juice left in that file, try paid options like Stellar or Wondershare as a last resort.
Never just delete the corrupt file either. Backup that bad boy because new tech or future methods might just bring it back to life someday.