fclones

Overview

Beyond grouping duplicates, fclones can remove or move redundant files, replace them with soft or hard links, or deduplicate file data with copy-on-write reflinks on supported file systems. You can inspect and modify duplicate lists before removal, and dry-run mode reports filesystem changes without applying them. Those review steps make potentially consequential operations more deliberate, though choosing which copy to keep remains your responsibility.

Key features

Scan scope is unusually adjustable: fclones accepts multiple directory roots and file lists from standard input, supports recursion limits, folder exclusions, glob and regular-expression filters, and can constrain results by minimum or maximum file size. It can work across directory trees and mounted or removable devices. Matching can use file size and inode or file identifiers, then prefix, suffix and full-content hashes. This range helps target large or specialized collections, but means more choices to manage than in a one-click cleaner.

Results can be written as standard text, fdupes-compatible output, CSV or JSON. JSON support and integration with Unix utilities such as find suit users who want to connect duplicate detection to other command-line work. File preview and automatic selection are also supported, though the project’s command-line format will not appeal to everyone.

The Rust implementation parallelizes I/O and CPU-heavy stages and tunes processing for SSDs and HDDs. Optional persistent hash caching can speed up repeat grouping and resume interrupted work. These are practical advantages for repeated or sizable scans; Linux users also get physical file-access ordering and page-cache drop-behind optimizations that are unavailable on macOS and Windows.

Copy-on-write reflinks can deduplicate file data without treating every redundant file as a simple deletion, but this operation depends on filesystem support and is not supported on Windows. The MIT license permits broad use, and GitHub Issues and Discussions provide community support.

Pricing

Open-source fclones is free under the MIT license. The free plan is the utility itself, with cross-platform coverage and no paid tier to choose between. That makes it a straightforward option for command-line users who need duplicate detection and file operations without a subscription; its trade-off is the command-line workflow rather than a graphical interface.

Platforms

fclones runs on Linux, macOS and Windows. Windows users lose copy-on-write file-data deduplication, while physical file-access ordering and page-cache drop-behind optimizations are Linux-only. The core duplicate-finding and file-management workflow is cross-platform, but the more specialized storage optimizations vary by operating system.

Who it's for

Choose fclones if you are comfortable with command-line tools and want to tune scan scope, inspect results before acting, or use output in a broader Unix workflow. Its filters, caching and multiple output formats are particularly useful when a fixed, visual cleanup routine is too limiting. Look elsewhere if you want a graphical interface or need Windows reflink deduplication.

Pros and cons

• Pros: Detailed scope and matching controls help target specific collections instead of scanning everything alike.
• Pros: Editable duplicate lists and dry-run reporting let you review file changes before committing to them.
• Pros: Text, fdupes-compatible, CSV and JSON output support both manual review and command-line workflows.
• Cons: The command-line approach is a poor fit for users who want a graphical cleanup process.
• Cons: Copy-on-write file-data deduplication is unavailable on Windows, and some I/O optimizations are Linux-only.

Alternatives

Duplicate File Finders is a useful starting point if you want to compare tools beyond a command-line utility.

Choose Czkawka if Android support matters; it is free across Android, Linux, macOS and Windows. dupeGuru is another free option for Linux, macOS and Windows. Anti-Twin is a free alternative for those platforms, with its Classic plan free for private use.

Duplicate Files Fixer may suit Android users or those who prefer a paid plan: its free version scans unlimited files but removes up to 15 duplicates at once, then one at a time; the paid plan costs 35.95 EUR per year. For a free, MIT-licensed tool focused on exact duplicate matching, consider jdupes. rdfind is another free option, released under GPLv2 or later.

Space Wizard offers a free home-drive plan with up to 100 GB per scan if that limit fits your needs. AllDup is free for private users and companies, but runs on Windows only.

Verdict

fclones is the right choice for command-line users who want careful control over duplicate scans, review before file changes and several ways to use results. Its free MIT-licensed distribution and adjustable workflow are the main reasons to choose it. Look elsewhere if you need a graphical interface, or if Windows copy-on-write deduplication is essential.