On Linux, you can use the following tools to find duplicate files.

https://github.com/adrianlopezroche/fdupes
https://github.com/arsenetar/dupeguru
https://github.com/jbruchon/jdupes
https://github.com/pauldreik/rdfind
https://github.com/pixelb/fslint
https://github.com/sahib/rmlint

On Linux, you can use the following tools to find duplicate files.

https://github.com/adrianlopezroche/fdupes
https://github.com/arsenetar/dupeguru
https://github.com/jbruchon/jdupes
https://github.com/pauldreik/rdfind
https://github.com/pixelb/fslint (Python 2.x)
https://github.com/sahib/rmlint
https://github.com/qarmin/czkawka (Rust)