By default, Windows 11 hides file extensions — so a file called document.docx shows as just “document”. This makes it harder to tell file types apart and is a minor security risk (malicious files can disguise themselves as something else). Showing file extensions is a simple setting change. Here is how.
Show File Extensions in File Explorer
- Open File Explorer (Win + E)
- Click the View menu in the top toolbar
- Hover over Show
- Click File name extensions
File extensions will immediately appear on all files in File Explorer. This is a global setting — it applies to all folders on all drives.
Alternative Method — Folder Options
- Open File Explorer
- Click the three dots (···) in the toolbar → Options
- Click the View tab
- Untick Hide extensions for known file types
- Click Apply → OK
Why You Should Always Show File Extensions
Hiding extensions causes two practical problems:
- It’s harder to tell files apart — a folder full of documents may contain DOCX, PDF, and TXT files that all look identical without extensions
- It’s a security risk — a file named “invoice.pdf.exe” displays as “invoice.pdf” when extensions are hidden. You might open it thinking it’s a PDF when it’s actually an executable file. This is a common technique used in phishing attacks
Showing extensions eliminates both problems.
Common File Extensions to Know
- .docx — Microsoft Word document
- .xlsx — Microsoft Excel spreadsheet
- .pdf — PDF document (read-only)
- .exe — Windows executable (program installer or application)
- .zip / .rar — compressed archive
- .jpg / .png / .webp — image files
- .mp4 / .mov — video files
- .txt — plain text file
- .csv — spreadsheet data in plain text format
How to Change a File Extension
With extensions visible, you can rename a file and change its extension directly. Right-click the file → Rename, then change the extension at the end of the filename (e.g. change .txt to .csv). Windows will warn you that changing the extension may make the file unusable — click Yes if you’re sure.
Note: changing the extension doesn’t convert the file format — it only changes the label. To genuinely convert a file (e.g. Word to PDF), use Save As or an export function in the application.
Showing Hidden Files
While you’re in File Explorer View settings, you may also want to show hidden files and folders — these include system files and folders that Windows hides by default. In the same View → Show menu, click Hidden items to toggle them visible. Hidden files appear slightly faded to distinguish them from normal files.
