How to Show File Extensions in Windows 10 and 11

By default, Windows hides the extensions of known file types. A file named “report.pdf” shows up as just “report” in File Explorer. You cannot see the extension at all.

To show file extensions in Windows 11: open File Explorer, click View, point to Show, then click “File name extensions” so it is checked. On Windows 10: open File Explorer, click the View tab on the ribbon, then tick the “File name extensions” checkbox.

That one setting is the whole answer for most people. Read on for steps on each platform. Showing extensions is one of the most practical security habits you can build on any computer.

Why Windows Hides Extensions by Default

Microsoft turned this off years ago to keep the desktop cleaner for everyday users. The idea was that most people do not need to see “.docx” or “.jpg” on every file.

The problem is that hiding extensions also hides the real type of a file. When you cannot see the extension, you cannot always tell what a file actually is.

The Security Risk of Hidden Extensions

Here is the threat that makes this setting worth changing.

A file named “invoice.pdf.exe” appears as “invoice.pdf” when extensions are hidden. To any reasonable person, that looks like a PDF. It is not. It is an executable program. Opening it can run malicious code on your computer.

This is a real attack technique called double-extension spoofing.

Turning on visible extensions means you will see “invoice.pdf.exe” in full. You will know something is wrong before you open it. Files with two extensions like that are almost always suspicious.

Seeing extensions protects you before a file can do harm.

When you download attachments or deal with unfamiliar files, the true extension tells you what you are actually dealing with. For formats like a .dat file or a .bin file, the extension tells you which program can open it.

Double extensions are a red flag. A file showing two extensions, such as document.pdf.exe or photo.jpg.bat, is almost certainly malicious. Never open it. Delete it immediately or report it to your IT team.

How to Show File Extensions in Windows 11

The setting is in the View menu in File Explorer.

  1. Open File Explorer (the folder icon in your taskbar, or press Windows + E).
  2. Click the View menu in the toolbar at the top.
  3. Point to Show in the dropdown.
  4. Click “File name extensions” so the checkmark appears next to it.

Extensions are now visible for all files. You do not need to restart or save anything. The change takes effect immediately across all open folders.

How to Show File Extensions in Windows 10

Windows 10 uses a ribbon interface rather than a menu bar, so the setting is in a slightly different place.

  1. Open File Explorer.
  2. Click the View tab on the ribbon at the top.
  3. In the Show/hide section, tick the “File name extensions” checkbox.

If you prefer the Folder Options dialog, there is an alternative path:

  1. In File Explorer, click the View tab, then click Options on the far right.
  2. In the Folder Options window, open the View tab.
  3. Find the line that says “Hide extensions for known file types” and uncheck it.
  4. Click OK.

Both methods do the same thing. The ribbon checkbox is faster.

How to Show File Extensions on a Mac

macOS hides extensions too, though it calls the setting something different.

  1. Open Finder.
  2. Click the Finder menu in the menu bar at the top of your screen.
  3. Choose Settings (on older macOS versions this is called Preferences).
  4. Open the Advanced tab.
  5. Tick the box next to “Show all filename extensions”.

From that point on, every file in Finder shows its extension. It is a global setting that applies to all folders and drives.

What You Can Now See

Once you turn the setting on, every file shows its true extension. A few things you will notice:

Many files you thought were one thing turn out to have extensions you have never seen. You might have a .torrent file you downloaded but forgot about, or an .apk file from an old Android project.

Seeing the extension is the first step to knowing what a file is and what you need to open it. For less common formats like .heic images from an iPhone, the extension tells you immediately why your usual image viewer might not open it.

Guides to Common File Types

Once you can see extensions, every unfamiliar format has an answer. Here are guides to some of the most common ones people encounter:

Frequently Asked Questions

Common questions about showing file extensions.

Will showing file extensions change any files?

No. The files themselves are not modified at all. It only changes what you see in File Explorer or Finder.

Should I turn file extensions back off?

There is rarely a good reason to. The default-off setting is a legacy choice. Keeping extensions visible is safer and more informative.

Why does a file have two extensions?

A legitimate file very rarely has two extensions. A double extension like “file.pdf.exe” is almost always a sign that someone is trying to disguise a program as a document. Treat any double-extension file as suspicious until you know otherwise.

Can I change a file’s type by renaming its extension?

Renaming the extension changes what the file looks like, but it does not change the actual content. Renaming “photo.jpg” to “photo.png” does not convert it to a PNG. The file format is determined by the data inside, not the extension name.

On Mac, why does only one file show its extension when I set “Show all filename extensions”?

A per-file setting can override the global preference. Right-click the file, choose Get Info, and under Name and Extension, uncheck “Hide extension”. The global setting applies to files that do not have a per-file override.

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