Frequently Asked Questions

RCompare is a fast, free, and open-source file and directory comparison utility written in Rust. It's inspired by commercial tools like Beyond Compare but focuses on speed, privacy, and modern architecture. RCompare can compare folders, text files, images, binary files, and archives.

Yes! RCompare is completely free and open-source under the MIT and Apache-2.0 licenses. You can use it for personal or commercial purposes without any cost. There are no premium features, subscriptions, or hidden fees.

RCompare runs on:

• Windows - Windows 10 and 11 (64-bit)
• macOS - macOS 11 (Big Sur) and later, both Intel and Apple Silicon
• Linux - Ubuntu 20.04+, Fedora 35+, Arch Linux, and most modern distributions

RCompare uses BLAKE3 for hashing, which achieves speeds of approximately 3GB/s on modern CPUs - significantly faster than MD5 or SHA-256. Combined with parallel directory traversal and a persistent hash cache, RCompare can compare millions of files efficiently while using minimal memory (~100-200 bytes per file).

No. RCompare operates 100% offline and never collects any data, telemetry, or usage statistics. Your files and comparison results never leave your computer. This is a core principle of the project.

RCompare supports:

• Directories - Full recursive comparison
• Text files - Any plain text with syntax highlighting
• Images - PNG, JPG, GIF, BMP, TIFF, WEBP
• Binary files - Hex comparison for any file type
• Archives - ZIP, TAR, TAR.GZ, TGZ, 7Z, RAR (read-only)

Yes! RCompare supports cloud and remote storage:

• S3/S3-Compatible - AWS S3, MinIO, DigitalOcean Spaces, Wasabi
• WebDAV - Nextcloud, ownCloud, Apache mod_dav
• SFTP - Any SSH server with SFTP support

RCompare maintains a persistent cache of file hashes to avoid re-computing them for unchanged files. The cache stores the BLAKE3 hash along with the file's size and modification timestamp. On subsequent comparisons, if a file hasn't changed, the cached hash is used instead of reading the entire file again. This dramatically speeds up repeated comparisons.

Cache locations:

• Linux: ~/.cache/rcompare/
• Windows: %LOCALAPPDATA%\rcompare\cache\
• macOS: ~/Library/Caches/rcompare/

In CLI output:

• == - Files are identical
• != - Files are different
• << - File exists only on the left side
• >> - File exists only on the right side
• ?? - Same size but not verified (use --verify-hashes)

Yes! The CLI supports JSON output for easy parsing:

You can also use --no-color to disable ANSI colors for cleaner log output.

Use the -i or --ignore flag with glob patterns:

RCompare also automatically respects .gitignore files in the directories being compared.

RCompare supports two diff algorithms:

• Myers - The classic algorithm that produces minimal diffs
• Patience - Better at preserving code structure and handling moved blocks

Both support intra-line (character-level) highlighting and 3-way merge for conflict resolution.

Contributions are welcome! You can:

• Report bugs or request features on GitHub Issues
• Submit pull requests with improvements
• Improve documentation
• Help with translations
• Spread the word about RCompare

Check out the GitHub repository for contribution guidelines.