How to Choose Which App Opens a File on Mac
Learn how to open a file with a specific app once, set a saved preference for a single file, or change the default app for an entire file type on macOS.
To open a file once with a different app, Control-click the file in Finder and select Open With. To always open a specific single file with an app, select it, press Command-I for Get Info, and choose an app under Open with without clicking Change All. To set a system-wide default for all files of that type, choose the app in Get Info and click Change All.
On this page
Choosing the Right Scope
macOS allows you to decide whether an app choice applies only once, to one specific file, or across all files of that type on your Mac.
| Intent | Action | Effect |
|---|---|---|
| One-time opening | Control-click the file in Finder > Open With, then select an app. | Opens the file in the selected app once without changing your saved defaults. |
| Single selected file | Select the file, open Get Info, choose an app under Open with, and do not click Change All. | The selected file opens with that app in the future, while other files of the same type remain unchanged. |
| All files of that type | Select a file, open Get Info, choose an app under Open with, click Change All, and confirm. | Changes the default opener for all matching files of that file type across this Mac. |
Step-by-Step Instructions and Reversal
To undo a preference, choose the previous app again at the same scope: one file or the file type.
- Select a representative file in Finder.
- To open it just once, Control-click the file and select Open With to choose an application.
- To save an app preference for that file, choose File > Get Info (or press Command-I), expand the Open with section, and pick an installed compatible app.
- Leave Change All unclicked if you only want the setting to apply to that individual file; click Change All and confirm only if you want it to become the default for that entire file type.
- To reverse the change, repeat the same steps within the same scope and pick the previous application.
- Verify your configuration by closing and reopening sample files.
Practical Examples and Limitations
Different tasks may call for different tools. For example, you might open one project Markdown note in a text editor while opening another in a distraction-free reader. Similarly, you might send an image to an editing program once while letting all other images open in Preview by default.
Choosing a different app or renaming a file extension does not convert the file format. If an application cannot read a file, check file compatibility and ensure the file is accessible; selecting an alternative app does not repair damaged or corrupted files.
Custom Openers in Project Groups
Within the Otterdock launcher, the Direct Full Pro edition supports assigning a custom opener to an individual file or file extension within your project dock. This setting applies specifically inside Otterdock and does not alter Finder defaults across your system. The Mac App Store edition does not include custom opener support.
Compare the available features in the Otterdock Direct and Mac App Store edition guide before choosing a distribution channel.
For the paid features within each edition, see the Free vs Pro comparison.