Set a new default PDF app in three steps

To change which app opens PDFs on your Mac, find a PDF file, right-click it, select "Open With," choose the app you want, then click "Change All." That single action changes the default for every PDF on your computer. The app you pick must already be installed on your Mac — you cannot set a default for software that does not exist on your system.

If you want to change the default only for one specific PDF (not all PDFs), use "Open With" but do not click "Change All." That opens just that one file in the app you chose, leaving your system default unchanged.

Key Takeaways

  • Right-click any PDF file, select "Open With," pick your preferred app, then click "Change All" to make it the default for all PDFs.
  • The app you choose must already be installed on your Mac; you cannot set a default for an app you have not downloaded.
  • If you only want to open one PDF in a different app without changing the system default, use "Open With" but skip the "Change All" step.
  • Your Mac comes with Preview as the default PDF app, but you can switch to Adobe Reader, Acrobat, or any other PDF app you have installed.
  • After you change the default, all PDFs will open in your new app when you double-click them or open them from email or web browsers.

Where to find the "Change All" button

The "Change All" button appears only when you use the "Open With" menu. To reach it: locate a PDF file on your Mac (in Finder, on your Desktop, or in Downloads), right-click the file, and a menu will appear. Look for "Open With" in that menu — it will show you a list of apps that can open PDFs.

At the bottom of the "Open With" list, you will see "Other." Click that if your preferred app does not appear in the initial list. A file browser will open; navigate to your Applications folder and select the app you want. Once you have selected an app, a button labeled "Change All" will appear at the bottom right of the dialog box. Click it, and that app becomes your default for all PDFs.

What happens after you change the default

Once you click "Change All," every PDF on your Mac will open in your chosen app by default. This affects PDFs you double-click in Finder, PDFs attached to emails, and PDFs you download from websites. The change takes effect immediately — you do not need to restart your Mac.

If you change your mind later, you can repeat the same process with a different app. There is no limit to how many times you can change your default PDF app. Your previous default does not get deleted or damaged; it simply stops being the app that opens when you double-click a PDF.

Common PDF apps you can set as default

Your Mac includes Preview, which is the built-in default. If you have installed other PDF apps, you can set any of them as your default instead. Adobe Acrobat Reader, Adobe Acrobat (the paid version), and third-party apps like PDF Expert, Skim, or GoodNotes all appear in the "Open With" menu if they are installed on your system.

Some apps are free to download from the App Store or the publisher's website. Others require payment. Before you set a new default, make sure the app is fully installed and working on your Mac. If an app appears in the "Open With" menu but will not open PDFs, try reinstalling it or checking the publisher's website for troubleshooting steps.

If your preferred app does not appear in the list

If the app you want to use is not showing up in the "Open With" menu, it may not be installed on your Mac yet. Download and install it first from the App Store, the publisher's website, or another trusted source. Once installation is complete, the app should appear in the "Open With" menu the next time you right-click a PDF.

If the app is installed but still does not appear, try restarting your Mac. Sometimes the system needs to refresh its list of available apps. If it still does not show up after a restart, the app may not support opening PDFs — check the publisher's documentation to confirm the app can handle PDF files.

Changing the default for specific file types within an app

Some PDF apps let you set additional preferences once they are your default. For example, Adobe Acrobat Reader has settings for how it displays PDFs, whether it opens in full-screen mode, and how it handles links. These settings live inside the app itself, not in the "Change All" menu.

To adjust how your default PDF app behaves, open the app, look for Preferences or Settings (usually in the app menu at the top of the screen), and explore the options there. Changes you make in an app's preferences affect all PDFs you open in that app going forward.

Frequently Asked Questions

Can I set different default apps for different types of PDFs?

No. Your Mac allows only one system-wide default PDF app. All PDFs will open in whichever app you set as the default. If you want to open a specific PDF in a different app, right-click it, choose "Open With," pick the app, but do not click "Change All."

What if I accidentally set the wrong app as default?

Simply repeat the process with the correct app. Right-click any PDF, select "Open With," choose the app you actually want, and click "Change All." Your previous default is not affected — it just stops being the one that opens automatically.

Will changing the default PDF app affect PDFs I already have?

No. Changing the default only affects which app opens when you double-click a PDF or open one from email or a browser going forward. The PDF files themselves are not changed or moved. You can always right-click any PDF and choose a different app to open it with, regardless of what your default is set to.

Does the default PDF app setting sync across my devices?

No. If you have multiple Macs, each one has its own default PDF app setting. Changing the default on one Mac does not affect your other Macs. You must change the default separately on each device if you want them all to use the same app.