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

By | November 5, 2014 | 3 Comments

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. Within Windows Explorer, right click on the file name, click on “Rename” and change the file extension to .bak and then again change it to uppercase/lowercase.
  2. You can use “rename” command from command prompt. For example use the following command to change the extension in batch
    rename *.PNG *.png
  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.

About Vishal Monpara

Vishal Monpara is a full stack Solution Developer/Architect with 13 years of experience primarily using Microsoft stack. He is currently working in Retail industry and moving 1's and 0's from geographically dispersed hard disks to geographically dispersed user leveraging geographically dispersed team members.

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

  1. Nimesh

    Thank you! Exactly the solution I was looking for. Well explained.

  2. 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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