OneDrive Sync Conflicts After Two Users Edit Offline

When two users open and edit the same OneDrive file while offline, both changes cannot be merged automatically. OneDrive detects the conflict after both users reconnect to the internet and attempts to sync their changes. This results in a sync conflict where OneDrive creates a separate copy of the file for one user. This article explains why offline edits cause sync conflicts, how to resolve them, and how to prevent future conflicts.

Why Two Users Editing Offline Creates a Sync Conflict

OneDrive uses a version-based sync engine. When a file is edited online, OneDrive tracks each change and merges them sequentially. When a user edits a file offline, OneDrive saves the local version but cannot communicate with the cloud server. If a second user also edits the same file offline, both local versions diverge from the cloud version. When both users reconnect, OneDrive sees two different file versions that both claim to be the latest. Because OneDrive cannot determine which version should overwrite the other, it creates a conflict.

OneDrive marks the conflict by appending the user’s device name and a timestamp to the filename. For example, Report.xlsx becomes Report-MyPC (conflicted copy 2025-03-15).xlsx. The original file is updated with the version that synced first. The conflicted copy remains in the same folder for the user whose sync arrived later. This behavior is by design to prevent data loss.

The conflict is not a sync error. It is a safety mechanism. The files are not corrupted. The user must manually resolve which version to keep or merge the changes.

Steps to Resolve OneDrive Sync Conflicts from Offline Edits

1. Identify the conflicted file in File Explorer
   Open File Explorer and navigate to the OneDrive folder. Locate the file with the words “conflicted copy” in its name. The file will also show a yellow warning triangle on its OneDrive sync status icon.
2. Open both versions of the file
   Double-click the original file (without the conflict label) and the conflicted copy. Compare the content side by side. For Office documents, use the Compare feature under the Review tab in Word or Excel to highlight differences automatically.
3. Merge the changes into one version
   Copy the changes from the conflicted copy into the original file. Save the original file. This ensures that the final version contains all edits from both users.
4. Delete the conflicted copy
   After merging, right-click the conflicted copy in File Explorer and select Delete. OneDrive will sync the deletion to the cloud. The original file now contains the complete content.
5. Notify the other user
   Send a message to the other user who edited the file offline. Confirm that the merged version is acceptable. If the other user still has the conflicted copy on their device, they should delete it after verifying the final version.

If OneDrive Still Shows a Conflict After the Main Fix

OneDrive created multiple conflicted copies for the same file

If both users edited the file multiple times while offline, OneDrive may generate several conflicted copies. Open each one and compare timestamps. Merge the latest changes from the most recent conflicted copy into the original file. Delete all outdated conflicted copies.

The conflicted file appears on the OneDrive website but not in File Explorer

This happens when the sync client on one device has not fully processed the conflict. Open OneDrive settings by right-clicking the OneDrive icon in the system tray and selecting Settings. Go to the Sync and backup tab and click Stop sync for that library. Wait 30 seconds, then click Start sync. This forces a full sync cycle that pulls the conflicted copy down to File Explorer.

OneDrive reports a sync conflict but no conflicted file is visible

The conflicted file may be in the OneDrive recycle bin. Open a web browser, sign in to portal.office.com, and open OneDrive. Click Recycle bin in the left navigation pane. Look for any file with “conflicted copy” in the name. Select it and click Restore. The file will reappear in its original folder and sync back to your device.

Files On-Demand vs Always Keep on This Device: Key Differences

Item	Files On-Demand	Always Keep on This Device
Description	Files appear online-only until opened, saving local disk space	Files are downloaded and kept synced locally at all times
Offline access	Only files explicitly marked as Always Keep are available offline	All files in the selected folder are available offline
Conflict risk during offline edits	Lower risk because most files are not available offline unless manually pinned	Higher risk because all files are available offline and can be edited by multiple users
When to use	When you want to minimize accidental offline edits and save disk space	When you need guaranteed offline access to all files in a folder

How to Prevent Sync Conflicts from Offline Edits in the Future

Enable Files On-Demand for all users

Files On-Demand ensures that files are not stored locally unless a user explicitly pins them. This reduces the chance that two users edit the same file offline because the files are not present on the local drive. To enable it, right-click the OneDrive icon in the system tray, select Settings, go to the Sync and backup tab, and under Files On-Demand, check the box for Save space and download files as you use them.

Set a file check-out policy for shared documents

In SharePoint or OneDrive libraries, you can require users to check out a file before editing. This prevents multiple users from editing the same file simultaneously. Go to the library settings in a web browser, select Library settings, then Versioning settings. Under Require Check Out, select Yes. Users must now check out the file before editing, which blocks offline edits by others.

Use co-authoring instead of offline editing

For Office files like Word, Excel, and PowerPoint, users can co-author in real time when they are online. This eliminates conflicts entirely. Encourage users to stay connected to the internet when editing shared files. If offline work is unavoidable, ask users to communicate with each other before making changes.

You can now resolve OneDrive sync conflicts caused by two users editing the same file offline. Use the conflict resolution steps to merge changes and delete duplicate copies. To avoid future conflicts, enable Files On-Demand and consider setting a check-out policy for shared libraries. For advanced protection, configure OneDrive sync settings to block sync of certain file types that are prone to conflicts.