Why SharePoint Online and OneDrive Show Different Storage Sizes
Question details
Understand the reasons behind the storage size discrepancy between a SharePoint Online library and the local OneDrive sync folder.
- Product
- SharePoint Online and OneDrive
- Device & OS
- not provided
- Scenario
- Monitoring storage usage and verifying complete synchronization of cloud libraries to a local machine.
- Observed behavior
- The SharePoint Online library displays a different total storage size compared to the same library synchronized locally through the OneDrive client.
Ensure your OneDrive client is fully updated and check the sync activity center to confirm that there are no pending file uploads or downloads.
Verify OneDrive Synchronization Status and Files On-Demand Settings
Check for unsynced files, naming restrictions, or online-only settings, which are the most common causes for storage size discrepancies.
OneDrive does not always download every single file from SharePoint to your local drive. Discrepancies often arise from Files On-Demand features, unsupported file types, or files blocked by organizational sync policies.
Click the blue OneDrive cloud icon in your system tray (Windows) or menu bar (Mac) to open the sync activity center.
Look for any warning signs or errors indicating that certain files failed to sync due to invalid characters in the file name, unsupported formats, or file path length limits.
Open File Explorer or Finder and right-click your synced SharePoint folder. Select 'Properties' (Windows) or 'Get Info' (Mac). Compare the 'Size' (total data) with the 'Size on disk' (actual local space used by downloaded files).
If you need the local folder size to match exactly, right-click the folder and select 'Always keep on this device' to force OneDrive to download all online-only files to your local drive.
Submit a Microsoft 365 Service Request for Backend Verification
If you suspect a service issue or the storage discrepancy is massive and unexplained, request backend verification from Microsoft Support.
Manage and Edit Synced SharePoint Documents with WPS Office
While resolving SharePoint and OneDrive synchronization discrepancies, you need a robust office suite to handle your local and cloud documents. WPS Office provides a lightweight, highly compatible alternative to Microsoft Office, letting you open and edit your synced files without eating up your local storage.
Frequently Asked Questions
Does the OneDrive Files On-Demand feature affect folder size calculations?
Yes. Files kept online-only appear in your local OneDrive folder but do not take up physical disk space. This makes the local 'Size on disk' significantly smaller than the actual SharePoint library size.
Can invalid file names cause a difference in storage sizes?
Yes. If a file in SharePoint contains characters not supported by Windows or Mac, or exceeds path length limits, OneDrive will fail to sync it. This results in missing files locally and a discrepancy in the total storage size.
How do organizational policies impact OneDrive sync sizes?
IT administrators can set policies that prevent certain file types (like media or executable files) from syncing to local devices. Because these files remain in SharePoint but do not download, your local folder will be smaller.
Does SharePoint include version history in its size calculation?
SharePoint storage quotas account for file version history and metadata, whereas your local operating system calculates the folder size based strictly on the current versions of the files synced to your drive.
