What can I do if Windows File Explorer indicates that a file name is too long?
What can I do if Windows File Explorer indicates that a file name is too long?
Symptoms
When using Windows File Explorer to rename a file on your Synology NAS with a file name that is allowed in File Station, you encounter an error message saying "The file name you specified is not valid or too long. Specify a different file name."
Diagnosis
This issue occurs because your file path length exceeds 244 characters, which could result from a long file name, long parent folder names, or having many layers of parent folders.
According to Windows regulations for files and folders on network drives, the maximum path length (MAX_PATH) for the Windows API is 260 characters. This includes a drive letter (e.g., E:\ taking up 3 characters), a folder path, a file name, and an invisible terminating NULL character (taking up 1 character).
Excluding the drive letter and the terminating NULL character, the maximum path length for creating, renaming, or moving a file/folder on a network drive is 244 characters.1 Exceeding this limit will prevent file operations such as saving, renaming, moving, or deleting.2
Resolution
- Move the file you want to rename to one of its parent folders to shorten the path length.
- Rename the file and make sure the new path is within 244 characters.3
Notes:
- The maximum usable path length is 244 characters as Windows File Explorer reserves 12 characters for the 8.3 file name format.
- This restriction applies only to Windows File Explorer and the Windows API. It does not affect file renaming with the
ren
orrename
commands in Windows PowerShell or Command Prompt. - You can use this website to count the number of characters in a file/folder name or a path.