Windows 10 File Extensions Not Showing: Seeing Whether a File Is .pdf, .exe, or Something Else

You download an invoice called “Invoice” and cannot tell whether it is a PDF, a Word document, or a program. Every file in File Explorer shows only its name, without .docx, .jpg, or .exe at the end. When Windows 10 file extensions not showing hides that part of the name, it is harder to rename files correctly and easier to be tricked by malicious ones.

A file extension is the short code after the dot that tells Windows which program opens the file. By default, Windows 10 hides extensions for known file types to keep names tidy.

That default causes real problems. A file named “photo.jpg.exe” appears as “photo.jpg,” hiding the slot mahjong fact that it is a program. Renaming files without seeing the extension can also leave you with “report.txt.txt.”

Showing extensions is a simple setting and a sensible security habit.

Possible Causes

Extensions are hidden for these reasons:

• “Hide extensions for known file types” is turned on by default.
• “File name extensions” is unticked in the View tab.
• A policy or tweak enforces the hidden setting.
• Folder view settings were reset after an update.

Some file types, such as shortcuts, always hide their extension by design.

Quick Fixes to Try First

Show extensions from the ribbon.

1. Open File Explorer.
2. Select the View tab.
3. Tick “File name extensions” in the Show/hide group.
4. Check a few files to confirm extensions now appear.
5. Close and reopen File Explorer to confirm the setting stays.

Once extensions are visible, use the Type column in Details view as a second check. It describes the file in plain words, such as “Application” or “PDF Document.”

Advanced Steps for Stubborn Cases

Use Folder Options and check for policies.

1. Select View > Options > Change folder and search options.
2. On the View tab, clear “Hide extensions for known file types” and select Apply.
3. Select “Apply to Folders” so every folder uses the setting.
4. If the box keeps turning back on, press Windows + R, type regedit, and check HideFileExt under HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced. A value of 0 shows extensions.
5. On work PCs, ask IT whether a policy sets this option.

When renaming a file with extensions visible, Windows warns you before changing the extension, which helps prevent mistakes.

Before You Go Further: Keep Your Files Safe

Be cautious with any file whose extension does not match what it claims to be, such as invoice.pdf.exe. Never open unexpected .exe, .scr, .js, or .vbs files received by email.

Conclusion

File extensions are hidden by default in Windows 10. Tick “File name extensions” in the View tab or clear the hide option in Folder Options to see what every file really is.