Duplicate and corrupted file detection apps?

Hi all,

For various reasons my backup discipline has become undisciplined, so I have a lot of files and folders to sort out. I'm a little worried - perhaps unnecessarily - about corruption in files or on drives that haven't been touched in a long time, and I definitely have accumulated a lot of unecessary duplicates, typically with the same content, sometimes with variations on the same content (e.g. resized images) and often with different names or dates.

I'm not really finding anything that will reliably detect corrupted files, and I'm guessing that it may not be possible without an original checksum to compare, but I guess it's possible a duplicate file finder might pick a fatally corrupted file with the same name up as the content might appear different? Or am I wildly wrong?

To duplicate files, there seem to be a lot out there and a lot of people seem to have their own favourite, but I'm not really finding a consistent recommendation for something that's simple to use, fast, safe and foolproof (except perhaps AllDup). Is there an 'industry standard'?

This guide will show you how to delete duplicate files in Windows using Command Prompt to free up disk space.