Command line utility written in Nim to find duplicate files. This program does not delete any files. It generates a list of duplicates in a specific directory for you to review and deal with as you see fit.

It is written to be acceptably fast and memory-efficient on modern hardware. Analyzing a directory of over 500,000 files of various sizes and types takes roughly 5 minutes and uses ~200MB RAM on my mid 2015 MacBook Pro.

So far ndf has been tested on OSX and Linux. It should work on Windows as well.

Install with nimble

nimble install ndf

Nimble will install ndf into ~/.nimble/pkgs/ndf-<version>/. To install ndf system-wide copy the binary it into a bin folder in your path, i.e.

cp ~/.nimble/pkgs/ndf-0.2.1/ndf /usr/local/bin/


$ ndf -h
ndf - Nim Duplicate Files Finder
Searches for duplicate files in directories.

  ndf [options] -d <dir_root>... -o <out_file>
  ndf (-h | --help)

  -d <dir_root>, --dir <dir_root>   Directory to scan. (Directory must exist and be readable)
                                    You can scan multiple directories by providing multiple -d switches.
  -o <out_file>, --out <out_file>   Output report file.
  -h --help                         This help message.
  -f --force                        Force overwrite target report file.

  ndf --dir /home/user --out duplicates.out
  ndf -d ~/Documents -d ~/Pictures -o report.txt -f

Sample run

Recursively scan directory test_files for duplicate files and save the results in report.out. Duplicate files will be grouped together.

$ ndf -d test_files/ -o report.out

Nim Duplicate Files Finder

Hint: Getting the list of files               ✔ Found 6 files in 3 file groups
Hint: Ignoring files with unique sizes        ✔ Found 5 files in 2 file groups
Hint: Getting file hashes                     ✔ Found 5 files in 3 file groups
Hint: Ignoring files with unique hashes       ✔ Found 4 files in 2 file groups
Hint: Writing final report                    ✔ Found 4 files in 2 file groups

$ cat report.out

+==> Group # 1 has 2 duplicate files:
| test_files/file1.txt
| test_files/file3d.txt

+==> Group # 2 has 2 duplicate files:
| test_files/.hidden_file
| test_files/a_subdir/file4.dat


  1. Fork it
  2. Create your feature branch (git checkout -b my-new-feature)
  3. Commit your changes (git commit -am 'Add some feature')
  4. Push to the branch (git push origin my-new-feature)
  5. Create a new Pull Request



Duplicate file finder written in Nim

Ndf Info

⭐ Stars 18
🔗 Source Code github.com
🕒 Last Update a year ago
🕒 Created 4 years ago
🐞 Open Issues 0
➗ Star-Issue Ratio Infinity
😎 Author rustomax