I recently noticed something strange in my OneDrive account. A large number of my files appear more than once, and I’m not sure whether this is a normal sync issue or something went wrong with my OneDrive setup. The duplicates include photos, documents, PDFs, and some older project files. In several folders, I can see multiple copies of files that I’m almost certain were originally uploaded only once.

Before deleting anything, I’m trying to understand what could have caused this. I use OneDrive on more than one device, so I’m wondering if files were synchronized repeatedly or if a conflict between local folders and OneDrive created additional copies. Microsoft’s guidance notes that sync conflicts can occur when files are changed or uploaded from multiple locations at the same time.

I also noticed that some duplicate filenames have a computer name added to them. Apparently, this can happen when OneDrive needs its cached credentials refreshed. Microsoft recommends checking Windows Credential Manager and removing relevant OneDrive cached credentials before restarting the application.

For people dealing with a large number of duplicates, manually checking every folder seems unrealistic. While researching possible cleanup methods, I came across SysInfo OneDrive Duplicate File Finder Tool . It looks like this type of software can help identify duplicate files across OneDrive rather than requiring users to compare folders individually. I’m interested in knowing whether anyone has actually used a duplicate-finding tool for a large OneDrive account.

There’s another issue I’m concerned about: deleting duplicates while OneDrive is still syncing. If the underlying synchronization problem hasn’t been fixed, removing the files might not solve the problem because the same copies could potentially appear again. Microsoft also recommends checking which folders are being synchronized and, where necessary, unlinking and reconnecting the account or resetting the OneDrive sync application.

I’m therefore considering a OneDrive Duplicate Remover only after making sure the synchronization itself is working correctly. I’d prefer to review detected files first instead of automatically deleting everything. Some files may look similar but could actually be different versions, so selective removal seems much safer.

Has anyone experienced a situation where OneDrive suddenly duplicated a large portion of their files? What actually fixed the problem for you—refreshing credentials, resetting OneDrive, changing sync settings, or using a dedicated duplicate finder? I’d especially like to hear from users who managed to clean up thousands of duplicate files without accidentally deleting their original data.