How to view a computer file extension

Updated: 11/30/2020 by Computer Hope

In Windows, you can view the file extension for a single file or all files, all the time. The method for viewing the file extension for a single file is the same in every version of Windows, but viewing all file extensions differs between versions. Select an option below and follow the instructions for viewing file extensions.

Note

To change a file's extension, see: How to change a file extension.
To change the default program that is associated with a file extension, see: How to associate a file with a program in Windows.

Viewing the file extension of a single file

  1. Right-click the file.
  2. Select the Properties option.
  3. In the Properties window, similar to what is shown below, see the Type of file entry, which is the file type and extension. In the example below, the file is a txt file with a .txt file extension. In this case, the file opens with the TextPad program.

Viewing file extension in Windows

Always show file extensions of all files

Users who are more familiar with computer files and file extensions may want to view file extensions permanently to help with locating and browsing files. To do this, follow the steps below for your version of Windows.

Windows 10

  1. Open the Control Panel.
  2. In the Control Panel, type file in the Search Control Panel text field. Click File Explorer Options in the search results.
  3. In the File Explorer Options window, click the View tab.
  4. Uncheck the box for the Hide extensions for known file type option.

Windows 2000, XP, Vista, 7, and 8

  1. Open the Control Panel.
  2. Click Folder Options.
  3. Click View.
  4. Uncheck the box for the Hide extensions for known file type option.

- OR -

  1. Open My Computer.
  2. Click Tools and click Folder Options or click View and then Options depending on your version of Windows.
  3. In the Folder Options window, click the View tab.
  4. Uncheck the box for the Hide file extensions for known file types option.

MS-DOS and Windows command line

In MS-DOS, typing dir to list all files also displays the file extension of each file.

Windows 98 and Me

  1. Open My Computer.
  2. Click View.
  3. Click Folder Options.
  4. Uncheck the box for the Hide file extensions for known file types option.

Windows 95

  1. Open My Computer.
  2. Click View.
  3. Click Options.
  4. Uncheck the box for the Hide MS-DOS file extensions for files that are registered option, then click Apply and OK.