FreeFileSync (latest release) is a free, open-source file-management utility that lets you compare and synchronise any number of folders in a single click. Drop two directories into the left and right panes, choose a sync variant and hit “Synchronise”—no file-count limits, no hidden fees.
Overview
FreeFileSync runs on Windows, macOS and Linux (Docker images available). It compares source and target, then transfers only changed or new data, giving you fast, byte-level accurate backups. Connect local drives, network shares (SMB), MTP devices or cloud storage (Google Drive, OneDrive, SFTP, FTP/FTPS) and sync in any direction.
Highlights
Platforms & storage: Windows, macOS, Linux; local disks, NAS, MTP mobiles, Google Drive, OneDrive, SFTP, FTP/FTPS.
Sync modes: two-way, mirror, update, custom (include/exclude filters, e.g., skip *.tmp).
Smart handling: detects moved/renamed files, copies locked files via Volume Shadow Copy, preserves NTFS permissions, extended attributes and long paths (> 260 chars).
Versioning & safety: keep old file versions, verify transfers with checksums, encrypt via SFTP/FTPS.
Automation: save configurations as .ffs_batch files and launch them from command line, cron or Task Scheduler; optional real-time monitor plug-in.
Interface: drag-&-drop GUI, colour-coded comparison, detailed HTML logs, 30 + languages.
Open source: no ads, no paywall, full source on GitHub; actively maintained (2025 adds native Google Drive API).
Core functions
- One-way or two-way sync between any two folders; tweak behaviour through the green-cog settings.
- Include/exclude filters (wildcards or regex) for fine-grained control.
- Binary or time-stamp comparison shows exactly what will change before you commit.
- No limit on file count or file size (> 4 GB supported).
- Full Unicode and long-path support; follows Linux symlinks and NTFS compression/encryption flags.