How to Change the Default App for a File Type on Mac

Double-clicking a file opens it in whatever app macOS has assigned to that file type, such as Preview for PDFs. You can change that assignment for a single file or for every file with the same extension.

Select a file of that type in Finder

Find any file with the extension you want to reassign, for example a .pdf or .mp4 file, and click it once to select it.

Open the Get Info window

Right-click the file and choose Get Info, or press Cmd + I.

Choose the app under Open with

In the Get Info window, expand the Open with: section if it is collapsed. Click the pop-up menu and pick the app you want. If the app is not listed, choose Other, find it in the Applications folder, and click Add. If the app is grayed out in that dialog, change the Enable menu from Recommended Applications to All Applications.

Click Change All

Click Change All under the menu, then click Continue to confirm. From now on, every file with that extension opens in the chosen app when you double-click it. Files already open are not affected until you reopen them.

Or set it for one file from the Open With menu

To change only a single file, right-click it, choose Open With, then Other. Select the app, check Always Open With at the bottom of the dialog, and click Open. That file opens in the new app from then on, while other files of the same type keep the old default.

If the change does not stick for some files. Files downloaded from the web or copied from another Mac can carry their own app assignment. Repeat the Get Info steps on one of those files and click Change All again; it applies to files with the same origin.

If you want a different browser or email app. Those are not file types. Set the browser in System Settings, Desktop & Dock, under Default web browser. Set the email app inside Mail: Mail, Settings, General, then Default email reader. Older versions of macOS (Monterey and earlier) keep the browser setting in System Preferences, General.