Your Mac has a neat setting that allows you to configure macOS to show all common filename extensions, such as .txt, .docx, or .jpg. This setting will let you differentiate what type of file you have and what app you can use to open it. File extensions are generally three or four characters long and appear at the end of filenames, separated by a period, like myphoto.gif. Here are some common file extensions you probably have on your Mac:
- .ppt or .pptx: PowerPoint presentation
- .key: Keynote presentation
- .gif: GIF image
- .png: PNG image
- .jpeg or .jpg: JPEG image
- .doc and .docx: Microsoft Word file
- .pdf: PDF file
- .txt: Plain text file
- .heic: High Efficiency Image File Format
Above are just a short list of examples. There are hundreds of different file types and extensions. By default, your Mac will not show file extensions; they are hidden.
You can make your Mac show file extensions for all files or for individual files.
You can use the Finder’s Preferences setting to see all of the file extensions for all files:
- Open a Finder window.
- From the top menu bar, select Finder > Preferences:
- Click on the Advanced tab and select the “Show all filename extensions” box. Now, most of your files will show their extensions. To turn this off, simply repeat these steps and deselect this box.
Show a single file’s extension
For various reasons, you may not want to see all file extensions. Alternatively, you can unhide an individual file’s extension. Here is how:
- In Finder, select a file by clicking on it to highlight the file. Then, do one of the following:
- Press Command–I.
- Right-click (Command-click) and select Get Info.
- From the menu bar at the top, Click on File, then Get Info.
- Expand the Name & Extension section by clicking the arrow next to it.
- Deselect “Hide extension.”
Now only this file will show its extension. If you want to stop showing its extension, follow the same steps, but this time select the “Hide extension” box.