How to Validate OneDrive Files After Migration in OneDrive for Business

After migrating files to OneDrive for Business, you need to confirm that every file arrived intact and accessible. Migration tools such as SharePoint Migration Tool or third-party services can sometimes miss files, corrupt data, or alter permissions. This article explains how to systematically validate your OneDrive files after migration using built-in tools and manual checks. You will learn how to compare file counts, verify folder structure, test file integrity, and confirm permissions without relying on guesswork.

Why File Validation After Migration Matters

When you migrate files to OneDrive for Business, the process involves copying data from a source location such as a local drive, network share, or another cloud service. Migration tools handle most files correctly, but several factors can cause problems. Network interruptions during upload can leave files partially uploaded. File name length limits in OneDrive can block files with paths longer than 400 characters. File types like .lnk or .tmp may be excluded by default. Permission inheritance may break if the source folder structure is complex.

Validation is the process of comparing the source data against the destination data to find discrepancies. Without validation, you risk losing business-critical documents, exposing sensitive data to the wrong people, or wasting time troubleshooting issues later. A structured validation approach reduces risk and gives you a clear record that the migration succeeded.

What You Need Before Starting Validation

Before validating, gather the following information: the exact source location and its total file count and size, the target OneDrive account name, and a list of any excluded file types or path length exceptions from your migration tool. You also need at least Read access to both the source and destination. For permission validation, you need administrative rights in OneDrive or SharePoint.

Steps to Validate OneDrive Files After Migration

1. Compare total file count and size
   Open File Explorer on the source location. Right-click the root folder and select Properties. Note the total file count and size. Then open the OneDrive folder in File Explorer. Right-click the same folder and select Properties. Compare the numbers. If the destination has fewer files or a smaller size, some files did not migrate. Repeat this for each subfolder if the root folder count does not match.
2. Check the OneDrive sync status
   In the system tray, click the OneDrive cloud icon. Ensure the status shows “Up to date.” If it shows a sync error or pending changes, click the icon and review the list of files that failed to sync. OneDrive reports files that exceed the 250 GB per file limit, contain invalid characters, or have path lengths over 400 characters. Resolve these issues by renaming or moving the files and then selecting Sync again.
3. Validate folder structure
   Open the OneDrive folder in File Explorer. Navigate through each top-level folder and compare its subfolder structure against the source. Use the tree view in File Explorer to expand folders. Look for missing or extra folders. If you find a missing folder, check the migration log for errors related to that path. If the folder is empty, some files may have been skipped due to naming conflicts.
4. Test file integrity by opening random files
   Select 10 to 20 files distributed across different folders. Open each file in its native application. For Office documents, check that the content renders correctly and that no images or links are broken. For PDFs, verify all pages are present. For images, confirm the resolution matches the original. If a file fails to open or appears corrupted, restore it from the source and re-upload it manually.
5. Verify permissions on shared folders
   Open the OneDrive web portal at onedrive.live.com. Navigate to a shared folder. Click the Share button and select Manage access. Compare the list of users and their permission levels against the source access control list. OneDrive supports sharing with specific people, Anyone links, and internal links. If a user is missing, reshare the folder with the correct permissions. Repeat this for all folders that were shared in the source.
6. Check the OneDrive recycle bin for migrated files
   In the OneDrive web portal, click Recycle bin in the left navigation. Look for files that were automatically moved there because they failed to upload correctly. OneDrive places files into the recycle bin when a migration tool reports a conflict or error. Restore any legitimate files from the recycle bin. Delete files that were intentionally removed during migration planning.
7. Run a file hash comparison for critical documents
   For high-value files such as contracts or financial spreadsheets, compute a hash value using PowerShell. On the source machine, open PowerShell and run Get-FileHash -Path "C:\source\file.xlsx" -Algorithm SHA256. On the destination machine running OneDrive sync, run the same command on the synced file. Compare the two hash strings. If they match, the file is identical. If they differ, re-upload the file from the source.

Common Validation Failures and How to Handle Them

File count does not match between source and destination

A mismatch usually means some files were skipped during migration. Open the migration tool log and search for errors with code 0x80070057 or “Item skipped.” Common causes include file names with trailing spaces, files locked by another application, or files exceeding the 15 GB per file limit in OneDrive. Rename the problem files on the source and rerun the migration for those items only.

OneDrive sync reports errors for certain files

If OneDrive shows a red X on a file, the file likely contains characters that OneDrive does not support, such as a tilde at the start or a colon in the name. OneDrive also blocks files with the extension .url or .lnk. Rename the file on the source to remove unsupported characters or change the extension to .txt for shortcut files. Then re-upload the file to OneDrive.

Permissions are missing after migration

OneDrive does not automatically migrate permissions from on-premises file servers. You must reconfigure sharing manually or use a tool like Microsoft 365 migration APIs to apply permissions. If users cannot access a folder they previously had access to, share the folder again from the OneDrive web portal with the correct user list. For large permission sets, consider using PowerShell cmdlets like Set-SPOSiteGroup to apply permissions in bulk.

OneDrive Files After Migration: Manual vs Automated Validation

Item	Manual Validation	Automated Validation
Description	Human compares source and destination using File Explorer and web portal	Scripts or tools compare file lists, hashes, and permissions programmatically
Speed	Slow for large migrations, can take hours	Fast, runs in minutes for thousands of files
Accuracy	Prone to human error, especially for deep folder structures	High accuracy, detects every discrepancy
Tools needed	OneDrive sync app, File Explorer, web browser	PowerShell, Microsoft Graph API, or third-party validation tools
Best for	Small migrations under 500 files or spot-checking	Large migrations with thousands of files and strict compliance requirements

You can now validate your OneDrive files after migration using the steps in this article. Start with a file count comparison and then check a sample of files for integrity. For critical documents, use PowerShell hash comparison to ensure no data corruption occurred. As an advanced tip, create a validation script that runs Get-ChildItem on both source and destination, exports the file lists to CSV, and uses Compare-Object to flag differences automatically.