Microsoft SharePoint and OneDrive Limitations

Certain characters have special meanings when used in file names in OneDrive, SharePoint, Windows and macOS, such as "*" for wildcards, and "\" in file name paths. If a file or folder you’re trying to upload to OneDrive contains any of the characters listed below, it may prevent files and folders from syncing. Rename the file or folder to remove these characters before you upload it.

• Tilde (~)
• Number sign (#)
• Percent (%)
• Ampersand (&)
• Asterisk (*)
• Braces ({ })
• Backslash (\\)
• Colon (:)
• Angle brackets (< >)
• Question mark (?)
• Slash (/)
• Plus sign (+)
• Pipe (|)
• Quotation mark (")

Invalid file or folder names

These names aren't allowed for files or folders: .lock, CON, PRN, AUX, NUL, COM0 - COM9, LPT0 - LPT9, _vti_, desktop.ini, any filename starting with ~$

Furthermore:

• "_vti_" cannot appear anywhere in a file name
• "forms" isn't supported when the folder is at the root level for a library.
• You can’t create a folder name in SharePoint Online that begins with a tilde (~).

Character Positioning

There are also restrictions about the positition of a character in a file/foldername:

• You cannot use the period character consecutively in the middle of a file/folder name.
• You cannot use the period character at the end of a file/foldername.
• You cannot start a file/foldername with a period character.
• If you use an underscore character (_) at the beginning of a file/foldername, the file/folder will be a hidden file/folder.

Network or mapped drives

You can't add a network or mapped drive as your OneDrive sync location. OneDrive doesn't support syncing using symbolic links or junction points.

File upload size

15GB
new 100 GB limit is rolling out now, and will be everywhere by early 2020

These limits apply to an individual file being uploaded or synced, not your total storage. For any file larger than a few GB, we recommend using the OneDrive sync app rather than the website upload feature.