Practical guide

Show File Extensions in Windows File Explorer

File extensions such as .pdf, .docx, and .jpg identify the file type. Showing them makes file management clearer, but renaming an extension does not convert a file.

What to do

  1. Open File Explorer and choose View > Show > File name extensions on recent Windows versions.
  2. On older layouts, open View > Options > View and clear Hide extensions for known file types, then select Apply.
  3. Check a file's complete name and use Properties if you are unsure what created it.
  4. Change a file type using the application's Save As or Export command rather than editing the extension by hand.

Checks and limitations

  • A file named report.pdf.exe is an executable, not a PDF; do not open unexpected attachments.
  • Renaming .docx to .pdf does not create a valid PDF and may make a file harder to open.