To show file name extensions in Windows 11, open File Explorer and select View > Show > File name extensions. In Windows 10, select the View tab and check File name extensions. Files with extensions then show names like report.docx or photo.jpg in File Explorer.
This guide covers Windows 11 and Windows 10, the Folder Options alternative, version-specific Settings, and how to identify an unfamiliar extension. The steps follow Microsoft’s Common file name extensions in Windows article. The routes below let you show extensions without renaming or converting your files.
How to Show File Name Extensions in Windows 11
- Open File Explorer. Press Windows key + E, or type file explorer in the search box on the taskbar and select it.
- Select View on the command bar.
- Point to Show at the bottom of the menu.
- Select File name extensions so it has a check mark.
Result: a file saved as report.docx should show that suffix in File Explorer. Files saved without an extension will not gain one. To hide them again, repeat the steps and clear the check mark.
How to Show File Name Extensions in Windows 10
- Open File Explorer with Windows key + E.
- Select the View tab on the ribbon.
- In the Show/hide group, check File name extensions.
Result: Check a file whose extension you know, such as a saved .txt document. Its full name should now appear. Clear the same check box to undo the change.
Other Ways to Turn On File Extensions
Folder Options (Windows 10 and 11)
- Open File Explorer Options (called Folder Options in some versions). You can search for it from the Start menu.
- Select the View tab.
- Clear the Hide extensions for known file types check box.
- Select OK.
Result: the change matches the File Explorer menu option, so either place shows the same setting.
Settings (Windows 11)
In Windows 11 version 25H2 and later, Microsoft documents System > Advanced settings. Open Settings > System > Advanced, find File Explorer and turn on Show file extensions. If that page is absent, use File Explorer or Folder Options above. You do not need to enable Developer Mode or change other switches.
Why Show File Extensions?
Microsoft explains that the extension, usually three or four characters after the period, tells Windows which app created or can open a file and which icon to show. In expenses.xlsx, for example, the extension is xlsx, an Excel workbook.
The last extension matters. For example, document.pdf.exe ends in .exe, which Microsoft identifies as an executable program; it is not simply a PDF. Showing the suffix helps you inspect a name, but does not prove the file is safe.
What If You Don’t Recognize an Extension?
Identify the ending before opening the file. If the source or expected format is unclear, ask the sender what created it instead of trying random apps. Showing extensions alone does not require opening the file.
- For a file from a source you trust, right-click it and select Open with > Choose another app to choose an installed app that supports its format.
- Select Open with > Search the Microsoft Store to find apps that can open that file type.
- Check Microsoft’s list of common extensions. For example, .csv is a comma-separated values file and .zip is a compressed file.
Microsoft adds that Notepad can open text-based formats. See How to open a CSV file in Notepad for an example.
Can I Change an Extension?
You can rename it, but Microsoft notes that changing the extension won’t convert the file to another format. Renaming .docx to .pdf, for example, just leaves a file that won’t open correctly. To choose which app opens a type of file, change the file association in Windows 11 instead, or use Save As or Export in the original app to create a real copy in another format.
Troubleshooting
- Extensions still don’t appear: press F5 to refresh the folder, or close and reopen File Explorer.
- Some files still have no extension: folders and shortcuts on the desktop don’t show one, and some files are saved without an extension.
- The option is greyed out or resets: on a work or school PC, your organization may manage File Explorer settings. Ask your IT admin.
Frequently Asked Questions
Are file extensions hidden by default?
Windows can hide extensions for known file types. If you currently see only the base name, enable the appropriate option above. This changes name display; it does not modify the contents of your files.
Does this also show hidden files?
No. Microsoft lists Hidden items as a separate option in the same View > Show menu in Windows 11, or the Show/hide group in Windows 10.
Source: Microsoft’s Common file name extensions in Windows and File Explorer in Windows. Related: How to add columns in File Explorer and How to create a zip file in Windows.
Start with the File Explorer route for your Windows version, then confirm the ending on a file you recognize. Leave extensions visible if you want to identify file formats more easily.
Matthew Burleigh is the founder, head writer, and editor of Solve Your Tech, which he launched in 2012. He has written technology tutorials since 2008 and worked in IT since 2003, including small-business support, IT management, and consulting. He holds Bachelor’s and Master’s degrees in Computer Science from Arizona State University.
Matthew writes practical guides for Windows, iPhone and iPad, Microsoft Office, Outlook, Google apps, and Android. Solve Your Tech’s guides are tested on current devices or checked against official product documentation, with clear steps, sources, and update dates.
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