fclones

fclones is a free, open-source command-line utility for finding identical files and managing redundant copies. It suits users who want precise control over scans and cleanup; its chief trade-off is that it expects comfort with command-line workflows rather than offering a graphical interface.

Overview

After identifying duplicate groups, fclones can remove or move extra files, replace them with soft or hard links, or deduplicate file data with copy-on-write reflinks on supported file systems. Users can inspect and edit duplicate lists before removal, and --dry-run reports filesystem changes without carrying them out. These options make it possible to choose a cautious workflow, but they also leave the decisions about what to keep with the user.

Key features

Scan controls include multiple directory roots, file lists supplied through standard input, recursion limits, folder exclusions, glob and regular-expression filters, and minimum or maximum file sizes. Scans can cover directory trees and mounted or removable devices. Matching can use file size, inode or file identifiers, prefix and suffix hashes, and full-content hashes, so users can tune the process to their collection rather than relying on a single matching method.

Results can be output as standard text, fdupes-compatible text, CSV or JSON. JSON support and integration with Unix utilities such as find make fclones suitable for scripted workflows as well as manual review. File preview and automatic selection are also supported, though the command-line orientation remains a poor fit for anyone seeking a visual cleanup experience.

The Rust implementation parallelizes I/O and CPU-heavy work and adjusts processing for SSDs and HDDs. Optional persistent hash caching can speed up repeated grouping and help resume interrupted work. These are practical advantages for large or recurring scans, while some performance optimizations are Linux-only: physical file-access ordering and page-cache drop-behind are unavailable elsewhere. Copy-on-write file-data deduplication is not supported on Windows.

Pricing

fclones is free: the Open-source fclones plan costs nothing and is released under the MIT license. It is a command-line utility, with no paid tier or trial to weigh against a free-plan cap. Its GitHub Issues and Discussions provide community support, rather than a paid support option.

Platforms

fclones is cross-platform, with support for Linux, macOS and Windows. The Windows limitation on reflink-based file-data deduplication means users who need that operation should choose another platform or tool. Linux users also get physical file-access ordering and page-cache drop-behind optimizations that are not available on macOS or Windows.

Who it's for

Choose fclones if you are comfortable using a command line and want to control where and how duplicate scans run, review results before changes, or connect output to other Unix utilities. It is less suitable if you want a graphical interface to guide file selection, or if Windows-based reflink deduplication is essential.

Pros and cons

• Pros: Detailed scan filters and several matching methods let users target large or specialized collections.
• Pros: Editable duplicate lists and dry-run reporting support a more deliberate cleanup process.
• Pros: Multiple output formats, Unix utility integration and persistent hash caching suit repeatable or scripted work.
• Cons: Its command-line design is not aimed at users who want a graphical file-cleanup workflow.
• Cons: File-data deduplication with reflinks is unavailable on Windows, and two performance optimizations are Linux-only.

Alternatives

Browse duplicate file finders for more options by category.

• dupeGuru is a free alternative for Linux, macOS and Windows if you want another cross-platform duplicate-file finder.
• Czkawka is free and adds Android support, making it a better fit if you need duplicate-file finding on that platform.
• Anti-Twin is a free alternative for Linux, macOS and Windows.
• Duplicate Files Fixer offers Android support and a free version that scans unlimited files but removes up to 15 duplicates at once, then one at a time; its paid plan costs €35.95 a year.
• Folder Size is Windows-only and focuses on folder and file-size analysis, disk-usage charts, and local and external drive scanning in its free plan.
• jdupes is a free, MIT-licensed option for exact duplicate matching across Linux, macOS and Windows.
• rdfind is a free option for Linux, macOS and Windows, released under GPLv2 or later.
• Space Wizard is a freemium alternative for Linux, macOS and Windows; its free plan covers a home drive and scans up to 100 GB per scan.

Verdict

fclones is a strong choice for command-line users who want configurable duplicate scans, reviewable results and multiple ways to handle redundant files without paying. Look elsewhere if you need a graphical workflow, or if Windows reflink-based file-data deduplication is a requirement.