How to Show File Extensions in Windows 11

Windows hides file extensions by default, so report.pdf shows as just report. That makes it hard to tell a real document from report.pdf.exe. Turning extensions on takes three clicks.

Open File Explorer

Press Windows + E, or click the folder icon in the taskbar.

Turn on file name extensions

In the toolbar at the top, click View. Hover over Show at the bottom of the menu, then click File name extensions so it has a checkmark.

Extensions appear immediately on every file, in every folder.

Also show hidden files, if you want them

In the same View, then Show menu, click Hidden items. This reveals files and folders Windows normally hides, like AppData.

Windows 10. The steps are the same, but the checkboxes live in the ribbon: click the View tab, then check File name extensions and Hidden items directly.

Why this matters. Malware often uses a double extension like invoice.pdf.exe with a PDF icon. With extensions shown, the .exe is visible and the trick fails.