Your computer has many types of files. Each file has a file extension. A file extension is a short code at the end of a file name. It usually has three or four letters. It tells you what kind of file it is and how to use it.

Examples of File Extensions

  • JPEG images use .jpg or .jpeg (example: image.jpg)
  • Word documents use .docx (or .doc for older versions) (example: CoverLetter.docx)
  • MP3 audio files use .mp3 (example: song.mp3)
  • Excel spreadsheets use .xlsx (or .xls for older versions) (example: budget.xls)

Hidden File Extensions

Some computers hide file extensions by default. This helps keep files looking neat. You can turn on file extensions if they are hidden.

Click the links below to learn how:

  • Windows
  • macOS

You can also guess a file type by its icon. A Word file has a "W" icon. An Excel file has an "X" icon.



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