There are default apps that open certain types of files in macOS High Sierra. However, you can change this. To open a file once with a specific app, do one of the following:
- Drag the file onto the app icon in the Finder or the Dock.
- Select the file in the Finder, choose File > Open With, then choose an app.
- Control-click the file, choose Open With, then choose an app.
- Open the app, then choose File > Open.
To permanently change the app used to open a file:
- In the Finder, select the file, then choose File > Get Info.
- You can also Control-click the file, then choose Get Info.
- In the Info window, click the disclosure triangle next to “Open with.”
- Click the pop-up menu, then choose the app.
- To open all files of this type with this app, click Change All.