File Sync Utilities for Windows

What counts as a file sync utility

A sync utility compares two locations (two local folders, a local folder and a network share, or local and cloud) and reconciles differences — typically copying new/changed files in one or both directions, and optionally deleting files removed from one side. This differs from a plain one-way backup copy in that sync tools track state over time and can handle bidirectional changes.

FreeFileSync

FreeFileSync is a free, open-source folder comparison and synchronization tool for Windows, macOS, and Linux, distributed from freefilesync.org. It supports one-way mirror and two-way sync modes, a visual diff of changed files before committing, and filters/exclusions. It's one of the more actively maintained dedicated sync tools available for Windows today.

SyncToy's status: discontinued

Microsoft's SyncToy was a free PowerToy-adjacent sync utility released for Windows XP/Vista/7 in the mid-to-late 2000s. It has been discontinued for years, is not tested or supported on Windows 10 or 11, and is not distributed through the Microsoft Store or an active Microsoft download page. Treat any current 'SyncToy download' offer with suspicion, and prefer a maintained alternative.

Robocopy as a scripted sync solution

For one-way mirroring, robocopy with /MIR (run on a schedule via Task Scheduler) is a no-install, built-in option — see our Robocopy basics guide. It doesn't offer true two-way sync or a conflict-resolution UI, but it's reliable, scriptable, and requires nothing beyond what Windows already includes.

OneDrive and other cloud sync

For syncing across multiple devices rather than between two local folders, OneDrive (built into Windows) or another cloud provider's sync client is usually a better fit than a folder-comparison tool. OneDrive handles continuous background sync, conflict versioning, and cross-device access, at the cost of storing a copy of your data in the cloud (subject to your plan's storage limit).

Choosing between them

A note on backup vs sync

Sync keeps two locations matching each other in near-real time, which means an accidental deletion or corruption on one side can propagate to the other. It is not a substitute for versioned backups. For anything important, pair sync with a separate backup strategy that retains older versions.