How to Change a File Type in Windows 10

To change a file type in Windows 10, open the file in an app that can read it, select File > Save As, pick the new format in the Save as type list, and select Save. Renaming the letters after the dot (the extension) only changes the file’s name. It does not convert what is inside the file.

Applies to: Windows 10 (version 22H2), with Microsoft 365 apps used as the Save As example.

File type and file extension: what actually changes

A file name extension is the set of characters after the last period in a file name, such as docx in expenses.docx. The extension tells Windows which app created the file or can open it, and which icon to show. The file type is the format of the data inside the file.

That gives you two different jobs that are often confused:

• Converting rewrites the contents in a new format. A Word document saved as a PDF is a real PDF. This is what most people mean by changing a file type. An XPS document works the same way: open it in XPS Viewer and print it to Microsoft Print to PDF, as shown in opening an XPS file in Windows 10.
• Renaming the extension changes only the label. You can change a file name extension, but it won’t convert the file to another format or change anything else about it except the file name.

Use this table to pick the right method.

What you want	Method to use
A document, spreadsheet or picture in a different format	Save As in the app that opens it
Fix a file that has the wrong or a missing extension	Rename the extension in File Explorer
Fix the extension on many files at once	The ren command
Make a file open in a different app	Change the default app (no conversion needed)

Before you start

• Keep the original. Save As creates a new file and leaves the first one alone, which is the safest way to work. Before you rename an extension, make a copy of the file.
• You need an app that can open the file and save in the format you want. Not every app offers every format.
• Know both formats. Common ones include .docx (Microsoft Word document), .xlsx (Microsoft Excel workbook), .csv (comma-separated values file), .pdf (Portable Document Format file), .txt (unformatted text file), .jpg or .jpeg (Joint Photographic Experts Group photo file) and .png (Portable Network Graphics file).

Convert a file with Save As

These steps use the Microsoft 365 desktop apps (Word, Excel, PowerPoint). Most other Windows apps have a similar Save As or Export command on the File menu, though the labels can differ.

1. Open the file in its app. If double-clicking opens the wrong app, right-click the file in File Explorer and select Open with > Choose another app to see the apps on your computer.
2. Select File, then Save As. If the file is stored on OneDrive or SharePoint, the command may be called Save a Copy.
3. Under Save As, select Browse, pick a folder, and type a name for the new file.
4. Open the Save as type list and pick the file format you want. For example, in Excel select PDF (*.pdf) to make a PDF copy of a workbook.
5. Select Save. The new file appears in the folder you picked, next to the untouched original.

The Save as type list also includes earlier versions of the app’s own format, which helps when someone with older software cannot open your file. A picture that needs to become a PDF has its own route: converting JPG to PDF on Windows 10.

Show file name extensions in Windows 10

You cannot edit an extension you cannot see. In Windows 10:

1. Open File Explorer by selecting its icon on the taskbar or the Start menu, or press the Windows logo key + E.
2. Select View > Options > Change folder and search options. A settings window opens.
3. Select the View tab.
4. In Advanced settings, clear the Hide extensions for known file types check box.
5. Select OK. File names now end with their extensions, such as report.docx.

The official file extensions help page, which covers both Windows 10 and Windows 11, gives the route View > Show > File name extensions. If your File Explorer has no Show menu, use the Options route above. To hide extensions again later, select the same check box again.

Rename a file’s extension in File Explorer

Rename an extension only when the label is wrong and the contents are already in the format you are typing. Typical cases are a text file that should end in .csv, or a file that lost its extension when it was sent to you.

1. Make a copy of the file and work on the copy.
2. With extensions showing, right-click the file and select Rename. The name becomes editable.
3. Replace only the characters after the last period with the new extension, and keep the period.
4. Press Enter. If Windows asks you to confirm the change, continue only if you are sure the new extension matches the contents, because a file with the wrong extension can stop opening.

Open the file to check that it still works.

Rename extensions on many files with the ren command

The ren command (also available as rename) renames files from a command prompt and accepts the wildcard characters * and ?. Like renaming in File Explorer, it changes names only and converts nothing.

1. Copy the files to a spare folder first so you have a backup.
2. Open a Command Prompt window.
3. Type the command with the folder path in front of the first name. To change every .txt file in a folder named Reports on drive C to .doc, type ren C:\Reports\*.txt *.doc and press Enter.
4. Open the folder in File Explorer and check the new names.

You can’t give a new drive or path for the second name, so ren cannot move files. If a new name matches a file that already exists, the command stops with the message Duplicate file name or file not found.

If the file just opens in the wrong app

A file that opens in the wrong program usually does not need a new type. Change the app Windows uses for that extension instead: open Settings, select Apps > Default apps, and set the default for that file type. Each screen is shown in setting default apps in Windows 10.

Confirm it worked, or undo it

• After Save As: look in the folder you chose. With extensions showing, you should see two files with the same name and different extensions. Open the new one and check the formatting, since some features do not carry over between formats.
• After a rename: open the file. If it no longer opens, rename it again and type the original extension back. Nothing inside the file was changed, so restoring the old extension restores the file.
• After ren: run the command the other way around, for example ren C:\Reports\*.doc *.txt, or go back to your backup copies.

Troubleshooting

The format I need is not in the Save as type list

The app cannot write that format. Look for an Export command on the app’s File menu, or open the file in a different app that supports the format. Some formats, such as OpenDocument, are listed at the end of the list, so scroll all the way down before giving up.

The file will not open after I renamed it

The new extension does not match the contents. Put the original extension back, then convert the file with Save As instead.

I renamed the file but the type did not change

Extensions are probably hidden, so you only edited the name in front of the real extension and ended up with something like photo.png.jpg. Show extensions with the steps above and check the full name.

I do not know which app opens the file

Right-click the file and select Open with > Choose another app to see the apps on your computer. You can also pick Open with > Search the Microsoft Store to look for an app that handles that extension.

Rename or settings are blocked

On a work or school PC, your organization may control folder options, default apps or the folders you can change. If the file is open in an app, close it before you rename it. For anything your organization manages, ask your IT administrator.

Frequently asked questions

Does renaming a .docx file to .pdf make it a PDF?

No. The file is still a Word document with a PDF label, and PDF readers will not open it. Open it in Word and use File > Save As with PDF selected as the type.

Is it safe to rename .jpeg to .jpg?

Yes. .jpg and .jpeg are the same Joint Photographic Experts Group photo format, so both labels describe the same contents.

Should I change the extension of a program or script file to make it open?

No. Extensions such as .exe (executable program file) and .bat (PC batch file) mark files that run code. Do not rename or run unfamiliar files of these types, whatever the source tells you to do.

Do these steps work in Windows 11?

Save As, Rename and ren work the same way. To show extensions in Windows 11, the path is View > Show > File name extensions in File Explorer.

Is Windows 10 still supported?

Microsoft ended support for Windows 10 on October 14, 2025, and version 22H2 is its final version. The steps here still work on a PC that runs it.

Microsoft’s reference pages for these steps are Common file name extensions in Windows and the ren command reference. Once your file is in the right format, open it one more time to confirm it looks the way you expect before you delete the original.