Dropbox to SharePoint migration

A setup reference for moving Dropbox content into SharePoint Online document libraries. Covers how to connect Dropbox, what carries across and what doesn't, how folders map into SharePoint, how large files move, how the connection stays signed in on long runs, and troubleshooting.

How the data flows

Files are read from the Dropbox API and written to SharePoint as they stream. Runs on your PC with MigrationFox Desktop send files straight from Dropbox to SharePoint. Cloud runs stream files through the MigrationFox worker, and files are not stored after the migration. MigrationFox only reads from Dropbox when it is the source.

Connecting Dropbox

On your project's Connect tab (or Add connection in MigrationFox Desktop), click Dropbox and pick one of two methods.

Recommended · Sign in with Dropbox (OAuth 2.0)

Sign in and click Allow

On the Connect tab, click Dropbox.
Choose OAuth 2.0 (in Desktop: Sign in), sign in to Dropbox and click Allow.
The connection appears as Valid, named after the signed-in account. Tokens are stored encrypted and refresh on their own.

What it can see: the signed-in account's own Dropbox, including folders shared with that account that appear in it. For a Dropbox Business account, sign in with your work account.

For quick tests · Access token (API key)

Paste a Dropbox access token

An access token generated in the Dropbox developer console also works, but these tokens are short-lived. Use one for a quick test only, and use sign-in for real migrations.

What carries across, and what doesn't

Carries across: files and folders, the folder hierarchy under the folder you pick, and file modified dates.
Dropbox sharing is not read. Shared-folder members, their access levels and shared links are not copied, so Migrate permissions has nothing to copy from a Dropbox source. Set up permissions in SharePoint after the move.
No team-admin access. MigrationFox reads one signed-in account's Dropbox. It can't use Dropbox team-admin access to read other team members' files. To move another member's files, connect as that member.
Dropbox Paper documents are not converted. They are not converted to Word. Export the Paper docs you need to .docx or .pdf in Dropbox first, then include those files in a run.
No version history. Only the current version of each file is copied. (Copy version history is offered for SharePoint, OneDrive and Box sources.)

Folder mapping rules

Root folder → library or folder. The Dropbox folder you pick as the source maps to the SharePoint library or folder you pick as the destination. Subfolder nesting below it is kept.
Invalid characters. Characters SharePoint doesn't allow in names (# % * : < > ? / \ | ") are replaced with underscores, and leading or trailing spaces and dots are removed.
Long names and paths. Name segments over 128 characters are shortened (keeping the extension), and paths over SharePoint's 400-character limit are shortened in the folder part so the file name stays intact. The pre-flight risk report after the scan lists affected items.
File request and camera upload folders are copied as regular folders. Their Dropbox-specific behavior doesn't carry across.

Large files

Uploads to SharePoint. Files up to 4 MB upload in one request. Larger files use SharePoint's resumable upload session in 10 MB chunks, so the file is never held whole in memory.
Downloads from Dropbox. Each file streams from a temporary download link. Dropbox API calls are retried with backoff on rate limits, server errors and network errors. If a download drops partway, the file is downloaded again, up to 5 attempts by default, before it is marked Failed.
SharePoint's per-file limit is 250 GB. Larger files are flagged in the pre-flight risk report and skipped during the run.

Staying signed in on long migrations

A large Dropbox migration can run for many hours. Both platforms issue short-lived access tokens, and MigrationFox renews them during the run.

Dropbox access tokens last about four hours. Sign-in stores a refresh token (encrypted) along with the access token, and a fresh access token is requested before the current one runs out.
Microsoft access tokens last about an hour and are renewed the same way.
Access tokens pasted by hand can't be renewed. A run longer than the token's lifetime fails once it expires, which is why sign-in is recommended.
If access is revoked mid-run (for example, an admin disconnects the app), files fail with an authorization error. Reconnect, then click Retry failed.

Running the migration

Connect both sides. Dropbox (sign-in) as the source, and SharePoint with Sign in with Microsoft as the destination.
Prepare the destination. Create the target SharePoint site and document library if they don't exist yet.
Scan first (optional). Choose Scan only to list the source without copying: counts, total size, and the pre-flight risk report (oversized files, long paths, invalid names).
Configure the job. Start from Other platforms. Pick the source folder and the destination library. MigrationFox sets the number of parallel transfers for the Dropbox and SharePoint pair automatically.
Run and monitor. Watch the job page. Failed files are retried automatically. Anything still failed at the end can be re-run with Retry failed.
Catch-up pass. Before cutover, run again with If file already exists at destination set to Incremental to copy only new or changed files. This check works for every cloud destination, including SharePoint, OneDrive, Dropbox, Google Drive and Box.

Troubleshooting

Symptom	Likely cause	Fix
The source picker shows fewer folders than expected	The connection is signed in as a different account (for example, a personal account instead of the work account), or the folders belong to another team member.	Reconnect with the account that owns or has the folders. Team-admin access to other members' Dropbox isn't supported.
Shared-folder members don't have access at the destination	Dropbox sharing isn't read as a source, so it isn't copied.	Set up permissions in SharePoint after the migration, ideally at the site or library level.
Large files keep failing	The download dropped on every attempt, or the destination site's storage quota is full.	Check the SharePoint site's storage quota. Then click Retry failed to re-run just the failed files.
The connection stops working after a few hours	It was set up with a pasted access token, which can't be renewed.	Reconnect with OAuth 2.0 sign-in, then click Retry failed.
Dropbox Paper documents missing or unreadable at the destination	Paper documents aren't converted to Word.	Export them to `.docx` or `.pdf` in Dropbox first, then include them in another run.
File names changed or shortened at the destination	Characters SharePoint doesn't allow, or SharePoint's name and path length limits.	Expected. Check the pre-flight risk report and the job's file list to see which items were affected.
Dropbox shared links no longer work after migration	Dropbox links are Dropbox URLs and don't carry over to SharePoint.	Create new SharePoint sharing links and tell people before cutover.

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