Incredible Free Open-Source File Backup App You Won’t Believe Exists

Backing up your files is undeniably crucial, yet the selection of effective methods can be overwhelming. While Windows has a built-in backup feature, its functionality is quite limited. On the other hand, quality backup software typically comes with a hefty price tag. Fortunately, FreeFileSync emerges as a robust solution to these challenges, providing an excellent balance of functionality and cost.

Introducing FreeFileSync

FreeFileSync is an open-source tool designed for file synchronization, enabling users to create exact duplicates of their folders effortlessly. Unlike traditional backup solutions such as Duplicati, which compress files into archives, FreeFileSync retains your data in its original format, ensuring easy access.

This efficient software supports four distinct synchronization modes:

Mirror: This mode generates a precise copy of your source folder.
Two-way: Changes are synced in both directions between folders.
Update: Only new or modified files are copied to the backup.
Custom: This mode allows users to define specific rules for file operations for enhanced flexibility.

Additionally, FreeFileSync excels in managing advanced backup configurations. It supports simultaneous syncing to multiple locations, making it an excellent choice for adhering to the 3-2-1 backup strategy—three copies of your data, stored on two different media types, with one copy kept offsite. The ability to chain multiple sync pairs in a single session means you can perform backups to both a local drive and a network location easily.

While alternatives like Duplicati and Macrium Reflect provide excellent full-system backup capabilities for Windows 11, FreeFileSync offers a more straightforward, quick solution for duplicating essential files and folders.

The core version of FreeFileSync is entirely free. However, it also features a Donation Edition that unlocks additional features, such as improved performance via parallel file operations. For most users, the free edition suffices, encompassing all necessary functions, with premium features catering primarily to those managing large datasets or utilizing slower connections.

How to Use FreeFileSync for Automated File Backups

While FreeFileSync is powerful, its interface may not be the most user-friendly, particularly for newcomers who may find navigating the setup process daunting without consulting documentation or support forums.

Once you familiarize yourself with the tool, establishing a basic backup is relatively straightforward. Here’s a simple example: let’s mirror a folder from your primary storage drive onto a secondary drive.

To initiate the process, click the + icon to designate your source folder on the left side—this is the folder you wish to back up. On the right, select your destination—this could be an external drive, a network location, or a cloud sync folder.

Before commencing the sync, it’s vital to adjust the comparison settings. Click the gear icon next to Compare (F6). The default setting, File time and size, works effectively for most scenarios. Only switch to File content if precise accuracy is required and you are prepared for a slower process, especially with larger folders. It is advisable to avoid File size comparisons unless you have advanced knowledge.

If your backup involves photos or videos, consider enabling Ignore time shift [hours] in the comparison settings. This option helps FreeFileSync prevent unnecessary re-copying due to minor time discrepancies, such as those occurring during daylight saving time adjustments or between Windows and a NAS.

FreeFileSync synchronization settings dialog

Next, configure your synchronization settings. Click on the green Gear icon next to the Synchronize tab and select Mirror mode. This setting ensures an exact replica of your source folder is created while removing any files from the backup that no longer exist in the original.

While Mirror mode is advantageous for maintaining a clean backup and avoiding clutter, it’s essential to note that this mode will also replicate corrupted files or those affected by ransomware. Moreover, if a file is deleted from the original, its counterpart in the backup will also be removed. To address these concerns, implementing file versioning, as outlined below, is advisable.

Alternatively, you can opt for the Update mode, which solely adds files to your backup without deleting any previously backed-up items.

The Two-way sync mode can be beneficial for specific scenarios, such as when collaborating on files stored in cloud storage.

Setting up Filters (F7) can help conserve space and time during backups. Access the filter settings by clicking the funnel icon, where you can exclude unnecessary folders or files from the backup process—like temporary files that can be recreated at a later date.

Always click Compare before initiating any sync to preview the changes FreeFileSync will execute, ensuring no unwanted modifications occur.

Enable Versioning for Backup Copies of Edited Files

To safeguard critical files from inadvertent modifications or deletions, activating versioning in FreeFileSync is essential. This feature keeps older versions of files, allowing recovery in case changes made during sync are undesirable.

In the main window, click the Gear icon next to Synchronization (F8) to access sync settings. Under Delete and overwrite, select the Versioning option. Click Browse to designate a location for the versioning folder—consider a path like E:\Backups\Versions.

Lastly, choose a naming convention; timestamps are a practical choice. This method enables FreeFileSync to retain backup copies of previous versions, providing a safety net if critical files are accidentally overwritten.

Automating and Scheduling Backups with FreeFileSync

Although FreeFileSync lacks a built-in scheduling feature, users can automate their backups by creating a batch file and scheduling it through Windows Task Scheduler. While this process may not be the most straightforward, it offers the convenience of setting it up once and letting it run automatically.

To do this, save your sync configuration as a.ffs_batch file. The batch job window offers customizable options, including whether the sync operates silently in the background, whether to display errors, and if a log file is generated.

It’s advisable to check the boxes for Run minimized and Auto-close if you prefer the task to execute without requiring interaction. Once saved, this batch file serves as a standalone script that you can run manually or configure Task Scheduler to execute automatically.

Consider saving each backup task as a separate batch file—one for daily document backups, another for video projects post-editing, and a comprehensive weekly backup for all other data.

For an alternative approach, you can utilize RealTimeSync, which comes with FreeFileSync. This tool monitors designated folders and triggers backups whenever files are modified. Unlike Windows Task Scheduler, RealTimeSync can detect and transfer files in real-time, making it ideal for users who want to back up changes immediately.

While the absence of native scheduling is a shortcoming, both Task Scheduler and RealTimeSync present viable solutions once properly configured. Always remember to test your scheduled tasks to avoid unexpected interruptions in your backup routines.

Moreover, FreeFileSync offers a portable version that can run directly from a USB drive, allowing users to implement backups on various computers easily. This feature makes it a convenient solution for quick and effortless backups.

Limitations of FreeFileSync

Despite its strengths, FreeFileSync’s interface appears somewhat outdated, reminiscent of design choices from 2010. While it fulfills the core functionality needed, the disorganized layout and technical terminology may confuse novice users, frequently necessitating research through documentation or video tutorials.

Additionally, FreeFileSync’s cloud support is limited. While it seamlessly integrates with Google Drive and accommodates FTP/SFTP connections, syncing with services like Dropbox or OneDrive can be cumbersome, requiring workarounds such as using their desktop applications or third-party tools like Mountain Duck to mount cloud storage as drives in File Explorer. Given that FreeFileSync is actively updated into 2025, this aspect feels surprisingly antiquated.

Download: FreeFileSync (Available for free, premium options offered)

Even with these drawbacks, FreeFileSync effectively covers the essential aspects of file backup. It’s a reliable, completely free solution devoid of advertisements, granting users comprehensive control over their backup strategy. While it primarily focuses on file and folder backup rather than full system imaging, it remains an excellent choice for protecting personal data, documents, and photographs.

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