Duplicate files

There are a lot of them, unfortunately it's usually just a case of try and find one that suits you

10 Best Free & Paid Duplicate File Finder & Remover for Windows 10 PC in 2021

Depends what sort of files you wish to search for duplicates, and the criteria you wish to use.
It would be dangerous, for example, to search Windows files for duplicates.

If you're considering your own, then you might need one that matches using a hash of the file e.g. md5 or similar.

For photos/images there are also programs that can find similar pictures.

Then consider audio or video files. You might have the same content recorded in different formats or resolutions.

What you need depends on what you want to achieve, and you would need to understand how the matching is achieved, and its implications.

Automatically deleting duplicates could be risky. I would never opt for that, personally.

I've used the 3rd party search program Everything.

Selecting the type of file and then sorting by size provides a list that you can look through and delete the ones you don't want. It works reasonably well if there aren't many duplicate files and you can recognize the unwanted duplicates. The best feature for me is that it finds files no matter where they are. I don't know how many times I've accidentally done a "drag-and-drop" to move files and accidentally dropped them into some random folder.

Here's an example that uses checksum comparison:
Free duplicate finder utility, remove identical files

When browsing a filesystem the file browser can show file checksum / hash value on demand in last column, allowing to identify binary identical files which have same checksum/hash value. the function (after rightclicking the file manager colum header) PeaZip file manager will display hash or checksum value for all (or selected) files. Clicking "Find duplicates" PeaZip file manager will work as duplicate finder utility, displaying size and hash or checksum value only for duplicate files - same binary identical content featured in two or more distinct files - and will report the number of non-unique files identified.

Then there are duplicate or similar finders in different file categories e.g. images:
Top 7 Best Photo Duplicate Finder and Removers in 2021

But again it's key to know and understand the basis on which items are categorised as 'similar' or 'duplicate'.

Richard Johnson said:

Looking to free up space on your hard drive? Duplicate Files Deleter can help! With its advanced scanning algorithm, this software can quickly and easily identify and remove duplicate files, freeing up valuable disk space and improving your computer's performance. Try Duplicate Files Deleter today and see the difference it can make!

Post #1 [of only 1] by a newly-registered user.
It reads like an advert & not like a genuine post.
What is your relationship with the makers of that software?

Denis