This is an application built as a personal project using wails.io and react. It is designed to help you hunt down exact matches of files (using a hash of the file contents) and then delete them and save yourself some disk space.
It's been developed on a Windows machine, but it should work on Linux and Mac, too, but I can offer no guarantees.
Just start up the application, select the directories you want to search, and then click the 'Search' button. It'll then go through all the files in the directories and subdirectories and build up a list of files that have the same content.