Batch File Renamer

Filename checker for Mac, Windows and OneDrive

A name that's fine on your Mac can fail to copy to a Windows drive, sync to OneDrive, or upload as a zip. Paste names below to see what would break and a safe version of each.

Download for macOSGet Pro

NameSafe nameProblems

The rules it checks

  • / can't be used in names on Mac or Windows. : shows as / in Finder and isn't allowed on Windows.
  • < > " \ | ? * aren't allowed on Windows, OneDrive or SharePoint.
  • CON, PRN, AUX, NUL, COM1–COM9 and LPT1–LPT9 are reserved on Windows, even with an extension.
  • Names ending in a space or dot are trimmed by Windows. Names starting with a dot are hidden on Mac.
  • Names longer than 255 characters fail on most file systems.

Fix a whole folder at once

Batch File Renamer's Remove and Replace steps strip or swap these characters across thousands of files, and the preview flags illegal characters, too-long names and clashes before anything is renamed. Lite is free.

Questions

Can Mac file names have colons?

Finder lets you type a slash, which it stores as a colon underneath. Windows, OneDrive and many zip tools reject colons, so avoid both.

What characters can't be in a Windows file name?

< > : " / \ | ? * and control characters, plus the reserved names CON, PRN, AUX, NUL, COM1–9 and LPT1–9.

Are my file names uploaded?

No. The check runs in this page.

Download Batch File Renamer

Download for macOS