The basic ways to open a file on your Mac
You open a file on a Mac the same way you would on any computer — by finding it and telling your Mac which program should open it. The most common method is to find the file in Finder (the folder icon in your dock), double-click it, and let your Mac choose the right program. If your Mac does not know which program to use, or if you want to use a different one, you can right-click the file and pick "Open With" from the menu that appears.
A second method is to open the program first, then use its File menu to open a document from inside that program. This works the same way on a Mac as it does on Windows — you click File, then Open, then navigate to the file you want. A third method is to drag a file directly onto a program icon in your dock or on your desktop, and the program will open the file if it knows how to read it.
Key Takeaways
- Double-clicking a file in Finder opens it with the program your Mac thinks matches that file type, which is usually correct.
- Right-clicking a file and choosing "Open With" lets you pick a different program if the default one is not what you want.
- You can drag a file onto a program icon in your dock to open it, and the program will refuse if it cannot read that file type.
- File extensions (like .pdf, .docx, or .jpg) tell your Mac which program should open a file, so changing or hiding an extension can break this.
Finding files in Finder before you open them
Before you can open a file, you need to know where it is. On a Mac, Finder is the program that shows you your files and folders — it is the equivalent of File Explorer on Windows. You open Finder by clicking its icon (a blue and white face) in your dock at the bottom of the screen, or by pressing Command+Space, typing "Finder", and pressing Enter.
Once Finder is open, you will see your Mac's hard drive and the folders inside it. Your personal files are usually in a folder called your username — you can click "Favorites" on the left side to see shortcuts to common places like Downloads, Documents, and Desktop. Downloaded files land in your Downloads folder by default. If you cannot remember where you saved a file, you can use the search box in the top right corner of any Finder window — type the file name or part of it, and Finder will show you every file that matches.
What file extensions are and why they matter
File extensions are the letters at the end of a file name after a dot — for example, .pdf, .docx, .jpg, or .mp3. These letters tell your Mac what kind of file it is and which programs can open it. When you double-click a file, your Mac looks at the extension and opens the program it thinks matches. If the extension is .pdf, your Mac will probably open it with Preview or Adobe Reader. If it is .docx, your Mac will open it with Microsoft Word or another word processor.
On a Mac, file extensions are often hidden by default — you might see a file called "Resume" instead of "Resume.pdf". This is usually fine, because your Mac still knows the extension is there. However, if you rename a file and accidentally delete or change the extension, your Mac may no longer know how to open it. If you want to see extensions, open Finder, click the Finder menu at the top left, choose Preferences, click the Advanced tab, and check the box that says "Show all filename extensions".
Using "Open With" to choose a different program
Sometimes your Mac will open a file with a program you do not want to use. For example, your Mac might open an image with Preview when you want to edit it in Photoshop, or open a text file with TextEdit when you want to use a different editor. To change which program opens a file, right-click the file in Finder and look for "Open With" in the menu that appears. You will see a list of programs your Mac thinks can open that file type.
If the program you want is not in the list, you can click "Other" at the bottom of the "Open With" menu. This opens a dialog where you can browse your Applications folder and pick any program on your Mac. Once you choose a program this way, that single file will open with it. If you want to change the default program for all files of that type, right-click the file, choose "Get Info", look for the "Open With" section, click the dropdown menu, pick the program you want, and then click "Change All". This tells your Mac to use that program for every file with the same extension.
Opening files from inside a program
You can also open a file by starting the program first and then telling it to open a file. This is useful if you know which program you want to use but are not sure where the file is saved. Open the program, click the File menu at the top, and look for an option that says "Open" or "Open File". A dialog box will appear showing your folders and files — navigate to the file you want and double-click it, or click it once and click the Open button.
Most programs on a Mac also show your recent files when you open them. If you used a file recently, you can often click File, then "Open Recent", and pick the file from a list without having to search for it. This is faster than navigating through folders if you remember the file name or know you opened it recently.
Dragging files onto program icons
A quick way to open a file is to drag it directly onto a program icon. You can drag a file from Finder onto a program icon in your dock (the bar at the bottom of your screen), or onto a program icon on your desktop. When you drag a file onto a program, your Mac will try to open the file with that program. If the program cannot read that file type, it will refuse to open it and the file will stay where it was.
This method is useful when you want to open a file with a specific program without navigating through menus. For example, you can drag an image file onto the Photoshop icon in your dock to open it in Photoshop, or drag a text file onto a code editor icon to open it there. The file itself does not move — you are just telling the program to open a copy of it.
Troubleshooting when a file will not open
If you try to open a file and nothing happens, or you get an error message, the most common reason is that your Mac does not have a program installed that can read that file type. For example, if you try to open a .psd file (Photoshop format) and you do not have Photoshop or a compatible program, your Mac will not know what to do. You can fix this by installing a program that reads that file type — search the App Store or the internet for the file extension to find programs that can open it.
A second common problem is that the file is corrupted or incomplete — for example, if a read was interrupted. Try downloading the file again or asking the person who sent it to you to send it again. If you are sure the file is fine and your Mac still will not open it, try right-clicking the file, choosing "Open With", and picking a different program. Sometimes a file can be opened by more than one program, and one might work when another does not.
Frequently Asked Questions
Can I change which program opens a file type permanently?
Yes. Right-click any file with that extension, click "Get Info", find the "Open With" section, click the dropdown menu, pick the program you want, and click "Change All". Your Mac will now open all files with that extension using the program you chose.
What does it mean when a file says "not supported" or "cannot be opened"?
Your Mac does not have a program installed that can read that file type. Search the App Store for the file extension (for example, ".heic" or ".webp") to find a program that can open it, or ask the person who sent you the file to send it in a different format.
Why are some files locked and how do I open them?
A file might be locked if it came from the internet or was sent to you by someone else. Right-click the file, click "Get Info", and look for a checkbox that says "Locked" — uncheck it if it is checked. Then try opening the file again.
Can I open multiple files at once?
Yes. In Finder, hold down Command and click each file you want to open, then press Command+O or right-click and choose "Open". Your Mac will open all of them, usually in the same program.
What if I want to open a file but do not know what program to use?
Try double-clicking the file and let your Mac choose. If that does not work, right-click the file, choose "Open With", and try each program in the list. You can also search the internet for the file extension to see what programs are designed to open it.