Have you just downloaded a work PDF and suddenly found the file has the extension of a text file (TXT) or even no extension at all? Well, luckily for you, there is an easy way for you to fix this in Windows 11. Whether you need to change a single file extension or change a whole folder full of them, you can change your file extension with a few clicks of the mouse.

File extension vs file type

File extensions are things like .png or .mp4 at the end of a file name. The file extension is not necessarily linked to the format of the file but instead just tells File Explorer how to open and read that particular file using the applications you have installed. A file type is the format that the file uses. An mp4 is a video file type, but the .mp4 in the file name is the file extension. Usually, these things should match, but it's possible for that not to be the case.

So, why would you need to change your file extension if it doesn't change the file type? Well, file extensions are kind of like labels for your computer. Sometimes files are given the wrong file extension (label) when you download them online. This doesn't mean that the file can't be used anymore, you just have to give it a new label so that your computer knows how to read it.

How to view file extensions in File Explorer

Before you can edit a file extension, you will need to be able to view them properly. To start:

1. Open File Explorer (Win+E) and go to the folder where your files are.
2. At the top of the window, click on View and choose Show > File name extensions.
3. You can now see the extension at the end of the file name.

How to change a file extension

Once you can see file extensions, it's easy to change them:

1. Open the File Explorer (Win+E) and navigate to the file whose extnesion you want to change.
2. Highlight the file that you want to change and then click on the file name to rename it.
3. Delete the old extension, then add a new extension.
4. A pop-up will appear asking if you're sure, Click OK. Once you're done, you can open the file, and it will open in the correct application.

How to change the file extension for multiple files at once

If you have a folder full of files that need new extensions, then you can use the Command Prompt to change multiple file extensions at once. Please make sure that your folder path is correct, as you do not want to convert the wrong files.

1. Open File Explorer (Win+E) and go to the folder of files you want to change.
2. Click on the address bar and type CMD.
3. Once the command prompt opens, type;

   ren *.png *.jpg

   You'll have to replace .png with the extension you're changing from and .jpg with the extension you want to change to.

4. Now hit Enter and all the files in the selected folder will have their extensions changed.

How to change file types in Windows 11

While changing your file extension is a relatively straightforward process, changing the file type or format is not as simple and will require a converting tool. For this example, we will convert an image file using iLoveIMG, to convert PNGs to JPGs. But you will need a different converter for different file types.

1. Search for and open the online converter iLoveIMG.
2. Select whether you want to convert to JPG or convert from JPG.
3. Now you can click the Select Images button, or drop the files you want to convert into the browser. You can convert one or multiple files at a time.
4. If you've added all the files you need to convert, then you can click Convert to JPG.
5. After the files have been converted, you can click on Download converted images if the download doesn't begin automatically.
6. You can now find your converted file(s) in your download folder.

Make sure to double-check every image that you converted for issues before you delete the original images.

Changing file extensions and types is easy

Now you know the difference between file types and file extensions, you should also have the necessary steps for fixing files with the wrong extensions to make them work properly, and be able to convert any files that you can't open with your current applications on Windows 11.