Fast Folder Mirroring for Reliable Backups

APIVoid Folder Mirror is a free Windows application that keeps a destination folder as an exact copy of a source folder, similar to robocopy /MIR but with a graphical interface. It copies new and changed files using parallel workers, deletes files that no longer exist in the source, and adds safety features such as dry run previews, mass-delete warnings, content verification, and file versioning.

Yes, all of our Windows software is digitally signed by NoVirusThanks Company Srl. This includes the installer, uninstaller, and the program's executable files.

Yes, APIVoid Folder Mirror is free to download and use. It is a Windows application that runs on Windows 10 and Windows 11. No account, sign-up, or subscription is required to use it.

Mirroring makes the destination identical to the source: new and changed files are copied, and files that were deleted from the source are also deleted from the destination. The result is a plain, browsable copy of your source folder. No special software is needed to restore it, just copy the files back. Because deletions are part of mirroring, APIVoid Folder Mirror adds several protections, including an optional warning when a large percentage of the destination would be deleted, a refusal to run when the source is unexpectedly empty, optional Recycle Bin deletion, and optional archiving of every deleted or overwritten file.

Yes. Save your folders and options as a named task, then run it from Windows Task Scheduler with command-line parameters such as /task:"Nightly Backup" /run /close. In this mode no dialogs are ever shown, so a scheduled run can never hang waiting for a click, and the process exit code reports the result: 0 for success, 1 for completed with errors, and 2 when the run could not start. Tasks can also be loaded from INI files with /task_file, which is useful for script-generated configurations. A Command-line.txt reference is installed with the program, or click on the main menu Help -> Command-line.

Two independent mechanisms are available. The "Exact content" comparison mode compares source and destination files byte-by-byte, with zero collision risk and early exit at the first difference. Separately, the optional "Verify files after copying" feature re-reads every copied file and compares xxHash3-64 or xxHash3-128 digests of the source and the new copy; the hash of each verified file is written to the log, and if verification fails the corrupted copy is deleted so the next run replaces it. This catches corruption caused by faulty cables, failing drives, or unreliable USB enclosures at backup time instead of at restore time.

By default they are removed or replaced, as mirroring requires. You can optionally send deletions to the Recycle Bin for easy undo, or enable the Archive feature, which moves every deleted file and every previous version of an overwritten file into a dated folder (one per run) that preserves the original folder structure. When the archive folder is on the same drive as the destination, archiving is an instant move rather than a copy, so it adds virtually no time to the run.

Yes. Both mapped network drives (such as Z:\Backups) and UNC paths (such as \\NAS\Backups or \\192.168.1.50\Backups) are fully supported as source or destination, including paths longer than 260 characters. For scheduled runs with Windows Task Scheduler, use the UNC path rather than a mapped drive letter: drive mappings belong to your interactive logon session and typically do not exist when a scheduled task runs in the background, while UNC paths work in any session. A few options behave differently on network shares: the destination volume identity check is skipped (the UNC path already names the server explicitly), the Recycle Bin option deletes permanently because network locations have no Recycle Bin (use the Archive feature instead if you want to keep replaced files), and ACL permission preservation requires a share that supports Windows ACLs, so it is best left disabled for Linux-based NAS devices.

Yes. Windows assigns drive letters on a first-come basis, so the letter E: can point to a different disk than it did yesterday. APIVoid Folder Mirror records the volume name and serial number of the destination after each successful run, and checks them before the next run of the same destination path. If the volume changed, an interactive run shows a clear warning with both identities, and a scheduled command-line run refuses to start. The destination's volume name and serial are also written to the log of every run.

Yes. The Advanced tab lets you configure an HTTPS webhook: when a run finishes (including runs that end with errors), APIVoid Folder Mirror sends a POST request with a JSON payload containing the status, task name, computer name, device model, user, source and destination, elapsed time, average speed, and full counters for copied, deleted, skipped, verified, and archived files. Requests can carry a custom authentication header (for example X-API-Key) managed through the built-in Auth Key Manager, where secret values are stored encrypted with Windows DPAPI. Self-signed certificates can be accepted by disabling certificate verification, and the request times out after 15 seconds.

No. All mirroring, comparison, verification, and archiving happens locally on your computer. Your files are never uploaded anywhere, and no telemetry is collected or transmitted. The only network request the program can make is the optional completion webhook, which you configure yourself, points to your own endpoint, and contains only run statistics and machine identification, never file contents.

No. In the current version, the program does not automatically check for, download, or install updates. To update to a newer version, you will need to manually download and run the latest setup file, which will overwrite the currently installed version on your system.

It is built for anyone who wants reliable, transparent folder backups on Windows: home users mirroring photos and documents to an external drive, developers keeping important project folders synchronized, and system administrators scheduling unattended nightly mirrors with webhook monitoring. If you like the simplicity of robocopy /MIR but want a GUI, saved tasks, fast file operations, verification, versioning, and safety rails, APIVoid Folder Mirror brings all of that together in one practical tool.