FreeFileSync: Compare Folders and Create a Mirror Backup
Compare the left and right folders and select the desired synchronization method from Update, Mirror, or Bidirectional. This guide covers installation, practical steps, limitations, and how to stop using the app.
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Who this guide is for and what to prepare
- First-time users of FreeFileSync
- People who want to check the storage location and safety of data while reducing manual work
What you need
- Check the processing target and storage location, and preserve the original data in another location
- Check the official distribution source, supported OS, and required permissions
When to use it
Compare the left and right folders and select the desired synchronization method from Update, Mirror, or Bidirectional.
Install the official version
Obtain the OS version from the official download of freefilesync.org, and prepare two empty test folders at first.
- Obtain the OS version from the official download of freefilesync.org and prepare two empty test folders at first.
Try it
Specify the source to the left and the backup destination to the right. View the copy direction and deletion candidates in [Compare]. Select [Update] or [Mirror] depending on your purpose. Set the version control destination for deleted files. Reconfirm the number on the [Sync] confirmation screen.
- Specify the source to the left and the backup destination to the right
- View copy direction and deletion candidates in [Compare]
- Select [Update] or [Mirror] according to your purpose.
- Setting the version control destination for deleted files
- Reconfirm the number on the [Sync] confirmation screen
Use it safely
Mirror deletes extra files at the backup destination. Do not run it without previewing the changes. Check the official business-use terms and Donation Edition features.
Turn it off or restore settings
By saving settings that you use repeatedly, you can reduce the need to reselect the left and right folders and synchronization method next time. However, if you replace the drive, recheck the path. When the manual execution is finished, close the screen and check the automatically executed task if you have created it separately.
Limitations and requirements
- Mirror deletes extra files at the backup destination. Do not run it without previewing the changes. Check the official business-use terms and Donation Edition features
- Check the current specifications in the official documentation and reconfirm on-screen what you want to delete or overwrite.
Frequently asked questions
What is the difference between update and mirror?
Update is used to reflect new/updated data from left to right, and mirror is used to align the right side with the left. Check the direction of the comparison result, as files on the right side only can be targeted for deletion in a mirror.
How do I restore it after accidentally deleting it?
Check the version control destination, recycle bin, and separate backup without performing the next synchronization. Whether it can be restored depends on the prior deletion processing settings, so it may not always be possible to restore it.
Official sources and verification date
Sources checked: . Check the official sources below for changes to supported systems, plans and menus.
Related practical guides
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- Sync vs Backup: Recovering from Accidental Deletion
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- Obsidian vs Joplin: Data Storage, Sync, and Encryption
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