Mac Fix Corrupted Files

petewinter used Ask the Experts™
I have various corrupted / damaged files on my mac os x. Unfortunately my backed up files are corrupt too.

So I am really hoping there is some software out there to fix corrupt / damaged files. Any suggestions?
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The only way I can think of getting back to good files is if you are running Time Machine and you could potentially go back to a time when the files were OK.
Scott CSenior Engineer

You are going to have to take this on a case by case basis.  

What kinds of files are we talking about?  Word, Excel, pictures, etc.

If each kind of file can be recovered, it will have to be by a utility that repairs that type of file.

There isn't going to be a "silver bullet" that will fix them all in one sweep.

How did your backup files get corrupted?  Were they backed up corrupted or were you possibly hit by a virus?


Old back up files from time machine are corrupt too.

I have a mixture of images, pdfs, indesign files, eps.

About a month ago an external hard drive wouldn't mount. I used data rescue 4 to recover files. Most were okay, but I have one folder with lots of files that I have just tried to use. All the files won't open.

Starting with PDF's. Is there a way to recover them?
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If all your time machine saves are also corrupt, the only thing I can think of is to send the disk to a service like Kroll Ontrack, but unless they're really valuable, it may not be worth the cost.

While this won't fix your current issue you may want to consider multiple backups.  What I do is Time Machine and then I take my most important files - documents, etc, emails and the like and back them up to iDrive which is a cloud-based service that will keep multiple versions of documents. You could also save them off to another source like a second external disk or USB stick.


Yes I have Dropbox set up now for everything. So there is no software that can recover corrupt files?
Senior Engineer
You can try this for your PDFs.

The evaluation mode puts a watermark on the page, but you will at least know if you want to pay to have them restored without the watermark.

Like I said, you're going to have to do this file type, by file type.  No one size fits all.
The other expert may be right that you may have to look for specific utilities.  However, you could try the following: make sure your files are copied elsewhere so that nothing else gets broken. In fact you may want a complete backup of the Mac, just in case. Boot your Mac from the Recovery partition like you're going to install a new copy of the OS.  When it gets booted, do NOT reinstall the OS. Instead go to the menu at the top of the screen and start Disk utility. In the utility select your disk and select to Verify disk and then when that finishes select to repair disk. This "may" fix some or all of your problems or nothing at all.

Another option that you may want to look at is Disk Warrior. It's a pay program that many users swear by, but again, it may not do anything - depending on why the files are corrupt.

If you used Data Rescue to recover these files and they are corrupt, you have no options. Data Rescue will recover parts of files (it usually marks them with a red label) and they'll look pretty normal until you try to open them.

Sorry, but these files are just simply nonexistent in their full form because of the data recovery.

Justin's response is 'right on the money'.  If you've already used Data Rescue .. and this is an external HD which failed you've probably got all you're going to get.
Time Machine only works on the main HD and if you copied these damaged files from the External HD to the main HD then TimeMachine will simply have backed up a damaged file as you've discovered.

Firstly, if DataRescue can find any part of a file it will create a "Recovered File" but unless it is 95% intact or is a pure text file most of the time these recovered files are useless and unusable.
Secondly, DataRescue can be used in a non-destrictive mode where it recovers files to your main HD and leave the damaged external device unaltered.  If that is the case you could try alternative data recovery software such as Stellar Phoenix Mac Data Recovery but you've already tried the top tool for the job so I'd probably not waste your time trying another one.  The OSX repair HD function in the Disk Utility application is always worth a try but I'm assuming you've tried that a long time ago.
Finally, there is another option which may be worth a try, I've used and trusted DiskWarrior ( for many years to repair and recover data from failing drives ... it is more focused on repairing a HD than recovering data but it has rarely failed me .. and if it fails the HD is usually terminally ill !!

Yeah, DiskWarrior is great but I'm guessing it's long past the point where you can use it with good results.
DW is pretty much just a directory repair tool. It does an amazing job repairing problems that other tools can't repair (and recovering files sometimes) but again, that's not your problem it seems.


Thanks for the help and advice

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