Turn on file extensions in File Explorer settings

File extensions are the letters after the dot in a filename — like .docx, .jpg, or .exe. Windows 10 hides them by default, which makes organizing files harder because you cannot see what type each file actually is. To show them, open File Explorer, click the View tab at the top, and check the box next to File name extensions. That is it. From that moment on, every file will display its full name including the extension.

The setting applies to all folders you open in File Explorer, not just one. Once you turn it on, it stays on until you turn it off again. You do not need to restart your computer or change anything else.

Key Takeaways

  • File extensions show you what type each file is — a .txt file is text, a .jpg is a photo, a .zip is compressed — so you can organize by type instead of guessing.
  • The View tab in File Explorer has a checkbox for file name extensions that applies to all your folders at once.
  • Showing extensions makes it obvious when a file has been renamed wrong or when a suspicious file is pretending to be something it is not.
  • If you ever need to hide extensions again, the same checkbox turns them off.

Why Windows hides extensions and why you should show them

Microsoft hides extensions by default because most people do not need to see them and the filenames look cleaner without them. But when you are organizing files into folders by type, or when you read something and want to know what it actually is, hidden extensions become a problem. You might think you have a photo called "vacation" when it is actually "vacation.exe" — a program file that could be dangerous.

Showing extensions also protects you from files that lie about what they are. A malicious file might be named "document.pdf.exe" — it looks like a PDF but it is actually an executable program. With extensions hidden, you would see only "document.pdf" and might open it thinking it is safe. With extensions visible, you see the .exe and know to be careful.

What each common extension means

Once you turn on extensions, you will see three-letter codes after the dot on almost every file. Here are the ones you will encounter most often:

  • .docx — Microsoft Word document (text and formatting)
  • .xlsx — Microsoft Excel spreadsheet (numbers and calculations)
  • .pdf — Portable Document Format (read-only, looks the same on any computer)
  • .jpg or .png — Image files (photos or graphics)
  • .mp3 or .wav — Audio files (music or recordings)
  • .mp4 or .avi — Video files (movies or clips)
  • .zip — Compressed folder (multiple files squeezed into one)
  • .exe — Executable program (runs when you double-click it)
  • .txt — Plain text file (no formatting, opens in Notepad)

If you see an extension you do not recognize, you can search for it online to find out what program opens it. Knowing the extension also helps you organize: you can put all .jpg files in a Photos folder, all .docx files in a Documents folder, and so on.

How to change a file extension safely

Once extensions are visible, you can rename a file and change its extension. Right-click the file, select Rename, and type a new name with a new extension if you want. Windows will warn you that changing the extension might make the file unusable — that warning is correct, so only change an extension if you know what you are doing.

The most common safe change is removing the extension entirely from a backup or copy of a file, or changing .jpg to .png if you need a different image format. Do not change a .docx to a .txt unless you want to lose all the formatting. Do not change a .exe to anything else — that will break the program.

File extensions in different Windows 10 views

The View tab in File Explorer has several ways to display your files: List, Details, Tiles, and Icons. File extensions show up in all of them once you check the box. The Details view is usually the clearest because it also shows the file size and the date you last changed it, all in columns you can sort by.

If you switch to Icon view or Tiles view, the extension appears below or next to the filename. In List view, it appears on the same line. Whichever view you choose, the extensions stay visible until you uncheck that box again.

Troubleshooting: extensions still not showing

If you checked the File name extensions box but extensions still do not appear, close File Explorer completely and open it again. Sometimes the setting does not take effect until you restart the program.

If that does not work, make sure you are looking at the right View tab. There is a View tab in the ribbon at the top of File Explorer — not in the menu bar. Click directly on the word View in the ribbon, and the checkbox should appear in the group labeled Show/hide.

On rare occasions, a setting in Folder Options can override the View tab. Open File Explorer, click File in the menu, select Change folder and search options, click the View tab, and look for an option that says Hide extensions for known file types. If it is checked, uncheck it. Click explore and then OK.

Frequently Asked Questions

Will showing file extensions break anything?

No. Showing extensions only changes what you see on screen. It does not change how Windows treats the files or how programs open them. You can turn extensions on and off as many times as you want without any risk.

Can I hide extensions for just certain file types?

Not easily. The checkbox in the View tab is all-or-nothing — it shows all extensions or hides all of them. If you want to hide extensions for specific types, you would need to change settings in Folder Options, which is more complicated and not worth the effort for most people.

What if I accidentally change a file extension and now it will not open?

Right-click the file, select Rename, and change the extension back to what it was before. If you do not remember the original extension, search online for the filename or the program that used to open it. Once you restore the correct extension, the file should open normally again.

Do I need to show extensions on external drives or USB sticks?

The setting applies to all drives and folders you open in File Explorer, including external drives and USB sticks. If you turn on extensions, they will show everywhere. You can turn them off again if you move the drive to a different computer.