Sync local and network folders with FreeFileSync: A complete guide

If you work with a lot of files between your PC and a network drive, you'll want to keep everything up to date without having to copy everything every time. In that scenario, FreeFileSync is a free and open source solution which makes it easy to create backups and keep two folders synchronized in Windows, macOS and Linux.

When we talk about synchronizing it does not mean cloning everything again, but detect what has changed and replicate only those differencesThis way of working saves time, reduces data transfer, and avoids headaches—something especially valuable with large folders or slower network locations.

What is FreeFileSync and why use it?

FreeFileSync stands out for its combination of simplicity and power: its interface is clear, but underneath it offers a good arsenal of options to adapt synchronization to each case. With it, you can Compare and synchronize local or network shared folders, configure filters, choose synchronization variants and save reusable profiles.

The tool allows different comparison methods: from the fastest and most common ones such as modification date and size, to binary content analysis for maximum precision (slower, but foolproof when you need total certainty).

In addition to synchronizing, it can behave as a backup solution with functionalities such as versioning and differential copies, so that only the modifications since the last execution are transferred and preserved.

In everyday use, one of its strengths is its versatility: FreeFileSync works consistently in Windows, macOS and Linux, generates detailed logs, alerts you to conflicts, and offers options to automate tasks and run them without intervention.

Comparison options and synchronization variants

Before synchronizing, FreeFileSync compares folders to identify which files are missing, which have changed, and which can be deleted based on your chosen rules. You can select comparison by date and size (fast and efficient in most scenarios) or by content (compares byte by byte for maximum security).

The interface displays a very clear timing view with the proposed changes, so you can review what will be copied, updated, or deleted. This preview reduces errors and allows you to fine-tune your configuration with confidence.

As for variants, modes such as Two-way to keep both folders the same (applying additions, modifications and deletions on both sides), duplication/mirror so that the destination is a replica of the source, and also real-time synchronization if you need constant reactivity.

For backup scenarios, you can work with differential copies to transfer only changes and enable versioning to preserve previous states, which is very useful when you want to recover a file as it was before a change.

The application incorporates automatic conflict detection (e.g., modifications to the same file on both sides) and suggests solutions to maintain consistency. It also generates detailed reports and logs to audit operations or detect problems in data-intensive environments.

How to use FreeFileSync step by step

Start by downloading the program from its official website: https://freefilesync.org/download.phpChoose the version for your operating system, run the installer, and follow the wizard; you'll be ready to go in just a few minutes.

In the main window you will see two panels, left and right. Click on Browse on each side to choose the folders you want to sync (source and destination, or just two replicas). You can use local locations or mounted network paths as drives.

With the folders defined, click on CompareFreeFileSync will analyze the differences and display a list of everything that can be synced. Review it carefully: if something doesn't match, apply filters, exclude folders, or adjust the sync option.

Select the synchronization variant which best fits. To keep two folders identical on both sides, the Two-Way option is best; if you want the destination to be an exact mirror of the source, choose Mirror. The preview will show you with arrows and colors what will happen to each file.

When you have it clear, press Synchronize and then Start. A window will open with detailed progress: processed files, speed, remaining time, and possible warnings. When finished, you can save a profile with all the configuration to reuse it.

FreeFileSync allows you to schedule the periodic execution of a task and export a profile for use from the consoleThis way, you can automate synchronizations with the system's task scheduler, ensuring your folders are always up to date without manual intervention.

Synchronize local and network folders

FreeFileSync works seamlessly with network shared folders, whether on a server, a NAS, or an office computer. Ideally, you should mount the network location as a drive or map it to a path accessible to the user you'll be using to perform the sync.

If you're using home NAS devices, like My Cloud Home, the usual flow is simple: first enables access to the local network and mount the network drive; then install FreeFileSync and define the folders in the left and right panels.

Once the unit is mounted, click on Compare, Choose the Synchronization variant (for example, Two Way when you want both sides to be identical) and run the sync with the corresponding button. You will see the progress until it ends.

Please note that some manufacturers indicate that They do not offer support for third-party software and that the use of external applications is at your own risk. It's common practice: always check their disclaimer and the NAS documentation to avoid misunderstandings.

In networks with many users or with slower links, it is advisable to use comparison by date and size To speed up the scan, apply exclusion filters (e.g., temporary or cache filters) and schedule synchronizations during off-peak hours.

Use case: sync C:\users\terra\documents\SYNCTHIS with \\myserver\terra\Sync\SYNCTHIS

Imagine you want to keep your local folder C:\users\terra\documents\SYNCTHIS up to date with the network shared folder \\myserver\terra\Sync\SYNCTHIS. In that case, avoid using the Windows Offline Files if it leaves your network drive unusable by showing only the cached content.

The practical alternative is to use FreeFileSync: in the left panel point to the local folder and on the right to the mounted network path (or the direct UNC). Run the comparison, review the preview and select Two ways if you want the network to reflect the local and vice versa, including additions, modifications and deletions.

To keep it in near real-time without saturating the network, create a scheduled task that launches the FreeFileSync profile at short intervals. This you automate synchronization and you avoid having to run it manually every so often.

If you are concerned about security in transit, consider your environment options: many corporate network implementations offer protocol-level encryption or secure tunnels. In alternative contexts, you can rely on tools that use end-to-end encrypted channels (mentioned below) when the workflow requires it.

As a good practice, save the profile with appropriate filters (e.g. exclude temporary, cache or system files) and activate detailed records to audit changes, especially in shared teams or critical projects.

Advanced features and useful utilities

FreeFileSync allows you to create profiles to restore your exact settings whenever you want, without having to rebuild everything. It's perfect if you do several different syncs (work, photos, projects, etc.).

Available inclusion and exclusion filters to limit what's synced. For example, you can exclude folders like .cache, temporary files, or extensions you don't want, thus speeding up operations and avoiding unnecessary backups.

When you compare by content, the process is more thorough and takes longer, but it guarantees a exact verification of changes. Use it in critical cases or when you suspect discrepancies in modification dates.

In projects where you need to preserve history, you can activate versioning to maintain multiple versions of files. This allows you to roll back if a change breaks something or if someone accidentally overwrites an important document.

Los reports and records They make monitoring production environments easier: you'll know what was copied, what was skipped, and why. If something goes wrong, the log is your best ally for diagnosing and correcting.

Alternatives and related tools

Depending on your organization's environment or policy, you may need other complementary solutions. These are known options covering different cases and protocols, all of them mentioned as valid alternatives:

• Rsync: A very flexible classic synchronization. It doesn't have a graphical interface by default, but Windows GUIs exist. It allows you to schedule frequent executions and offers encryption options if you use it over secure channels.
• FullSync: Java-based directory synchronization tool with support for multiple protocols (FTP, SFTP, SMB, etc.). Requires Java Runtime Environment.
• Nextcloud Desktop Client: : synchronization client between your computer and a Nextcloud server, useful for collaboration and persistent remote access.
• ownCloud Desktop Client: equivalent solution focused on ownCloud servers, with file synchronization between devices.
• Rclone: line utility commands to manage and synchronize data with more than 40 cloud providers (S3, Google Drive, OneDrive, FTP, SFTP, WebDAV, etc.). No installation required: unzip the zip and run rclone.exe.
• syncthing: P2P synchronization between nodes with TLS/SSL connections. No installation required either: just unzip and run syncthing.exe.
• Synchronous: Utility to synchronize several folders at once, with pre-scanning, blacklists and options to restore replaced files.
• Unison: Designed to maintain two consistent replicas on different machines. No traditional installation required: unzip the zip file and run unison-gui.exe.

If you work a lot with cloud services or remote protocols, a combination of FreeFileSync for local/SMB environments and Rclone or rsync for specific destinations can cover virtually any workflow.

Good practices when synchronizing on the network

Before launching a first synchronization, make a previous comparison and carefully review the change view. It's the simplest way to avoid impulsive deletions or desynchronizations due to a poorly chosen option.

Define exclusion filters to discard Temporary files, caches and elements that do not add value. This reduces There process and wear storage, especially on shared networks.

If your network is slow or very busy, favor the comparison by date and size To save time, reserve content comparison for spot audits or verification when there are questions.

Save profiles with clear names (for example, TwoWay_Work or Backup_Photos_Duplication) and create a scheduled task that runs them when you are not there, thus avoiding forgetfulness and load peaks during usage times.

Activate the detailed records and save them to a known location. If anything goes wrong, reviewing the log will give you immediate clues about which option changed or which file caused a conflict.

Common usage scenarios

For regular backups, FreeFileSync fits like a glove: you can keep several versions of your documents and use differential synchronization to move only the changes, saving time and space.

When working multi-device, two-way sync keeps your laptop and desktop connected. always aligned, so you have access to the latest versions wherever you are.

In project teams, sharing a network folder and synchronizing changes ensures that everyone is working on the same updated files, minimizing conflicts and loss of time due to duplications.

If you organize media libraries or personal documents, synchronization helps maintain a coherent structure in different locations, while archiving allows you to separate the historical from the active.

In high data volume environments, the combination of profiles, filters, logs and scheduled tasks creates a flow reliable and repeatable which reduces human errors and downtime.

Support, security and reliability

FreeFileSync has a active community and extensive documentation. While some manufacturers (such as Western Digital) state that they don't offer support for third-party software, you'll find guides and forums with practical recommendations.

In terms of performance, the program takes advantage of techniques of optimization and batch processing to speed up the copy. However, the final speed will depend on your network, storage, and the comparison method you choose.

Regarding security, consider your environment options (e.g., encrypted links, appropriate permissions, and network policies). If you need end-to-end encryption, consider tools that operate over secure channels or protocols that guarantee it according to your case.

To minimize risks of corruption or loss, use the versioning, periodically check your logs, and set up content checks when appropriate. A small investment in prevention can help prevent big scares.

FreeFileSync offers just what many need: a clear and powerful way to synchronize local and network folders, with modes for almost any scenario, from differential copies with versioning to bi-directional synchronization, including programming Automatic and reusable profiles. By combining best practices (pre-comparison, filters, logs, and scheduled tasks) and, when appropriate, relying on alternatives like rsync, Rclone, or Syncthing, you can set up a robust, fast, and secure workflow without complicating your life.