Change your default PDF app in System Settings

To change which app opens PDF files on your Mac, you use System Settings rather than the app itself. Open System Settings, click General in the sidebar, then scroll down and click Default apps. Find PDF in the list — it will show your current default app next to it — and click that app name to see other options installed on your Mac.

The apps that appear depend on what you have installed. Preview (which comes with every Mac) is usually the default. Other common choices are Adobe Acrobat Reader, PDF informed, or any web browser. Select the app you want, and it takes effect when ready. The next time you double-click a PDF file or click a PDF link in email or a web browser, the new app will open it.

This method works on macOS Ventura and later. If you have an older Mac, the steps are slightly different — you would right-click a PDF file, select Open With, choose your preferred app, then click Change All to make it the default for all PDFs.

Key Takeaways

  • System Settings > General > Default apps is where you change which app opens PDF files on modern Macs.
  • Your choice takes effect when ready and applies to all PDF files you open going forward.
  • Preview comes built into every Mac, but you can choose any PDF reader you have installed instead.
  • If you have an older Mac, right-click a PDF file and select "Change All" to set a new default.
  • Changing the default app does not delete or move your PDF files — it only changes which program opens them.

Why you might want to change your default PDF app

Preview works well for basic PDF reading and annotation, but some people prefer a different app for specific reasons. Adobe Acrobat Reader offers more advanced form-filling and signature tools. PDF informed or similar apps provide faster search across many documents. Some people straightforward prefer how another app looks or organizes tools.

You might also change your default if you installed a new app and want to test it before committing. You can always switch back to Preview or any other app using the same System Settings path. There is no penalty for changing — your PDF files stay exactly where they are.

What happens when you change the default

Changing the default app affects only how new PDFs open. Any PDF files you already have stay in their current location and do not move or change. If you had a PDF open in Preview when you switch to a different default app, that file stays open in Preview until you close it.

The change applies to PDFs you open by double-clicking them, PDFs you read from the web, and PDF links in email or web pages. It does not affect PDFs that are already set to open with a specific app through other means — for example, if you right-clicked a PDF and selected "Always Open With" a particular app, that file will still use that app even if you change the system default.

If your preferred app does not appear in the list

If the app you want to use is not showing in the Default apps list, it may not be installed on your Mac, or it may not be registered as a PDF reader. First, make sure the app is actually installed by checking your Applications folder. Open Finder, click Applications in the sidebar, and look for the app by name.

If the app is installed but not in the Default apps list, try opening a PDF file with that app manually. Right-click the PDF, select Open With, and look for the app there. If you find it, click the app name and then click Always Open With. This tells macOS that the app can handle PDFs, and it should then appear in System Settings the next time you check.

If the app still does not appear, contact the app's developer or check their support page — some smaller PDF readers do not register themselves as default app options on macOS.

Changing the default for a single PDF instead of all PDFs

If you want one specific PDF to open with a different app but do not want to change your system default, right-click the PDF file and select Open With. A menu appears showing available apps. Click the app you want to use for that one file.

This opens the file but does not change your default. The next PDF you open will still use whatever app you set as the default in System Settings. If you find yourself always opening certain PDFs with a different app, that is a sign you might want to change your system default instead.

Troubleshooting when the default does not change

If you set a new default app but PDFs still open in the old one, restart your Mac. Sometimes macOS does not fully register the change until you restart. Shut down completely, wait a few seconds, and turn the Mac back on.

If restarting does not work, check that you actually clicked the app name in the Default apps list and confirmed your choice. It is straightforward to click the wrong spot and think you changed it when you did not. Go back to System Settings > General > Default apps, find PDF again, and verify which app is listed next to it now.

If you are still having trouble, try opening a PDF with your preferred app using the right-click menu and selecting Always Open With. This is a more direct way to set the default and sometimes works when the System Settings method does not.

Frequently Asked Questions

Can I set different default PDF apps for different folders?

No — macOS only allows one system-wide default app for PDFs. However, you can right-click individual PDFs and open them with a specific app without changing the default. If you regularly work with PDFs in different ways, you might keep multiple PDF apps installed and choose which one to use each time.

Will changing my default PDF app affect PDFs I have already opened?

No. PDFs that are currently open in an app will stay open in that app. The change only affects PDFs you open after you make the change. If you want an already-open PDF to switch to your new default app, close it and open it again.

What if I want to go back to Preview as my default?

Go to System Settings > General > Default apps, find PDF, and click the current app name. Select Preview from the list. Preview is always available on every Mac, so you can always switch back to it at any time.

Does changing the default app delete or move my PDF files?

No. Your PDF files stay exactly where they are on your Mac. Changing the default app only changes which program opens them — it does not touch the files themselves or move them to a different location.