4 ways to change the file extension to uppercase/lowercase in Windows

By | November 5, 2014

Have you ever had a situation where you needed to change the file extension to uppercase/lowercase in windows? Here are quick and easy steps to accomplish this task.

In order to view the file extension in Windows Explorer (aka “My Computer” aka Windows Start menu > Computer), you need to enable the settings. Go to Windows Explorer and press “ALT” key once which will open up menu (For older version of Windows, this menu is always visible.). Click on “Tools” menu > “Folder Options…”. Under “View” tab, “Advanced Settings” option, uncheck the box “Hide extensions from known file types” and click “OK” button.

  1. Change the file extension to .bak and then again change it to uppercase within Windows Explorer.
  2. You can use “rename” command from command prompt.
  3. When you create a new file, at the time of saving, you can specify uppercase extension. If that does not work, wrap the file name with extension in quote character (“). So instead of specifying abc.txt in the Save dialog box, use “abc.txt” (use quote characters around file name).
  4. You can “Save As” existing file and specify the uppercase extension. Use the trick specified in #3 if extension is not retained.

2 thoughts on “4 ways to change the file extension to uppercase/lowercase in Windows

  1. amit

    thanx a lot.
    ur submission gave me a better idea for batch processing
    i have done in command prompt
    just a little command

    ren *.extension1 *.extension2

    all the files can change extension/uppercase/lowercase and also no intermediate .bak change is required.

    eg: ren *.jpg *.JPG will change the case from lowercase to uppercase

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