Files with similar icons can contain very different types of data. Showing file extensions in Windows exposes the suffix after the last dot, making a name such as invoice.pdf.exe easier to distinguish from a PDF.
An extension such as .txt or .jpg helps Windows choose the app used to open a file. Changing the extension does not convert its contents and can stop the expected app from opening it.
The File name extensions option in File Explorer changes how filenames are displayed for your Windows user account. It applies across folders without renaming the files or changing which apps open them.
Steps to show file extensions in Windows 11:
- Open a folder containing files in File Explorer.
The Win + E shortcut opens File Explorer.
- Open the View menu in the File Explorer command bar.
- Open the Show submenu.
- Enable File name extensions.
A checkmark beside File name extensions means it is already enabled. On Windows 10, the option is on the View tab.
- Confirm filenames include their extensions, such as .txt, in the file list.
A name ending in invoice.pdf.exe identifies an executable, even if its icon resembles a document.