How to Show File Extensions
Why showing extensions matters
When extensions are hidden, a file named invoice.pdf.exe can appear as invoice.pdf. That disguise is one of the reasons attackers rely on hidden extensions.
Showing extensions gives you a quick way to compare the visible label with the actual file type before you open it.
Windows
Open File Explorer, select the View menu, and enable File name extensions in the Show group. In Windows 11, open the View dropdown and switch File name extensions on.
The change applies to new and existing Explorer windows, so you do not need to restart your computer.
macOS
Open Finder, choose Settings (or Preferences on older macOS), select Advanced, and clear Hide extensions. Existing files with hidden extensions will now display them.
To reveal a single file quickly, select it and choose Get Info, then change the Name & Extension setting for that file.
Android and iOS
Android file managers differ by app. In Files by Google, open the three-dot menu in a folder and check Show file size and Show storage usage; extension visibility depends on the app and file type.
On iOS, the Files app shows full filenames in most list and grid views. If you cannot see an extension, use Get Info for the selected file to inspect its name.