How to fix filenames that break OneDrive sync on Mac

What this does

macOS allows characters in filenames that Windows based cloud sync services like OneDrive simply refuse to upload, things like a colon, an asterisk, or a question mark. If you’ve ever seen a sync error mentioning invalid characters, this is usually why. This rule strips out that whole set of troublesome characters automatically, so a file is safe to sync before it ever gets there.

What you’ll build

A rule that matches every real file, then removes any character from its name that cloud sync services commonly reject.

Open the rule editor

This walkthrough happens inside FilesAutomator itself, so install it from the Mac App Store first if you have not already, then open it. In its toolbar, choose Add, then New Automation Rule.

Name the rule and choose a folder

Name it something like “Strip characters that break my cloud sync” and use Add Folder to choose your synced folder.

Build the condition

Add a single condition: Size is greater than 0, matching any real file.

FilesAutomator

Add the action steps

Step 1: Rename

Choose Add Step, then Rename. In “New name, built from the parts below”, use Add Part, then Find and Replace in Name. Turn on “Find is a pattern”, since this is a character pattern rather than a literal string, enter this pattern to find:

["*:<>?/\|]

Leave the replacement empty, so every match is simply removed. Add Part again, choose Text, type a period, then Add Part once more and choose Extension.

FilesAutomator

Turn it on

Select Create Automation Rule, then switch the rule on. Every file that lands here now gets a name your cloud sync service will actually accept.

A faster way

The template gallery inside FilesAutomator already has this rule ready to install, named Strip characters that break cloud sync.