How to See File Extensions on Windows, Mac, and Other Platforms

File extensions are the short suffixes at the end of a filename — the .jpg, .pdf, .docx, or .mp4 that tell your operating system (and you) what kind of file you're dealing with. Most modern operating systems hide extensions by default, which keeps things looking clean but can leave you guessing what a file actually is. Here's how to bring them back into view — and why it matters which setup you're running.

What File Extensions Actually Are

Every file on your computer has a name and an extension. The extension follows a dot at the end of the filename and signals the file format — which determines what software can open it and how the OS handles it.

For example:

• report.docx — a Microsoft Word document
• photo.png — a PNG image file
• budget.xlsx — an Excel spreadsheet
• song.flac — a lossless audio file

When extensions are hidden, you see only report, photo, budget, song — with a generic icon standing in. That's often fine for casual use, but it creates real problems when you need to convert files, troubleshoot compatibility issues, or spot disguised malware (a common trick is naming a malicious executable invoice.pdf.exe, which looks harmless when the extension is hidden).

How to Show File Extensions on Windows 🖥️

Windows hides extensions by default, but turning them on is straightforward — and the exact steps vary slightly depending on your Windows version.

Windows 11

1. Open File Explorer (the folder icon in your taskbar)
2. Click View in the top menu
3. Hover over Show
4. Click File name extensions to toggle them on

Windows 10

1. Open File Explorer
2. Click the View tab in the ribbon at the top
3. Check the box labeled File name extensions

Windows 7 / 8

1. Open File Explorer or Windows Explorer
2. Go to Organize → Folder and search options
3. Click the View tab
4. Uncheck Hide extensions for known file types
5. Click Apply

Once enabled, extensions appear on every file in that Explorer window — and stay on across sessions unless you reverse the setting.

How to Show File Extensions on macOS 🍎

Mac also hides extensions by default, but exposes them through the Finder preferences.

For all files system-wide:

1. Open Finder
2. Click Finder in the menu bar → Settings (or Preferences on older macOS versions)
3. Go to the Advanced tab
4. Check Show all filename extensions

For a single file:

1. Right-click the file → Get Info
2. Look at the Name & Extension section — the full filename including extension appears here
3. Uncheck Hide extension if you want it visible in Finder going forward

The system-wide setting applies globally but individual files can still override it through their own Hide extension option in Get Info.

File Extensions on Linux

Linux systems generally show extensions by default in file managers like Nautilus (GNOME), Dolphin (KDE), or Thunar (XFCE) — but this depends on your distribution and desktop environment. If extensions are hidden in your file manager, look for a View or Preferences menu and check for a "show file extensions" or "show hidden file information" option.

In the terminal, extensions are always visible. Running ls in any directory displays full filenames including extensions exactly as stored on disk.

Viewing Extensions on Chromebooks and Mobile Devices

Chromebook: The Files app on ChromeOS shows extensions for most file types by default. If a file's extension isn't visible, you can check it by right-clicking → Get info.

Android and iOS: Mobile operating systems are more aggressively abstracted — apps open files based on MIME type associations, and raw extensions are often not shown to users at all. You can see extensions on Android through file manager apps like Files by Google or third-party managers that display full filenames. On iOS, the native Files app shows extensions inconsistently; many third-party file managers handle this more reliably.

A Quick Reference by Platform

Why the Right Setting Depends on Your Situation

Showing extensions is almost always useful for anyone who works regularly with files — developers, designers, writers managing document formats, or anyone handling downloads from the web. But the degree to which it matters shifts based on your workflow.

If you work primarily within a single app ecosystem (say, only ever opening files through specific applications), hidden extensions rarely cause problems. If you frequently move files between platforms, convert formats, write scripts, or need to verify what a file actually is before opening it, visible extensions become genuinely important rather than just convenient.

There's also a security dimension: seeing extensions in full is one of the simplest ways to spot files that are pretending to be something they're not. This matters more on Windows, where executable extensions like .exe, .bat, and .vbs are particularly relevant, than on systems where execution permissions work differently.

The setting itself is a toggle — easy to reverse. But whether leaving extensions visible fits naturally into your day-to-day workflow, or creates more visual noise than it resolves, depends entirely on how you interact with your files.