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How to change which app opens PDFs on your Mac

PDFs opening in Chrome, Acrobat or the wrong app? Set the default PDF viewer on a Mac for every PDF in Finder's Get Info, and see why it keeps changing.

The problem

You double click a PDF and it opens in a browser tab, or in an app you installed once and forgot about. On our test Mac, seven different apps said they could open a PDF, and any of them can end up as the one that does.

How do I change the default PDF viewer on a Mac?

Select any PDF in Finder, press Command I, choose the app under Open with, and click Change All. Every PDF on the Mac opens in that app from then on.

  1. Select any PDF in Finder and choose File > Get Info, or press Command I.
  2. Open the Open with section.
  3. Choose the app you want, for example Preview.
  4. Click Change All, then Continue to confirm.

How do I make Preview open PDFs again?

Use the same steps and pick Preview. Preview is what a Mac uses for PDFs until something changes it, so choosing it with Change All puts things back as they were.

How do I open one PDF in a different app without changing the default?

Control click the PDF, choose Open With, and pick the app. The default stays as it was.

Which apps on my Mac can open a PDF?

More than you might think. On our test Mac the list under Open with had Preview, Books, ColorSync Utility, Safari, Chrome, Simply PDF and a chat app. Any app that tells macOS it can read PDFs joins that list when you install it.

Read on 16 October 2026 on a MacBook Air (M1), macOS 27.0.1, from the list macOS keeps of apps that can open a PDF, the same list Get Info shows.

How do I check which app is the default?

Get Info on any PDF shows it under Open with. In Terminal, this prints the choice macOS has saved for PDFs:

defaults read com.apple.LaunchServices/com.apple.launchservices.secure LSHandlers | grep -B2 -A2 com.adobe.pdf

If it prints nothing, no app has ever been chosen for PDFs, and they open in Preview. That is what our test Mac showed.

Why does my default PDF viewer keep changing?

Usually because an app asked to become the default and someone said yes. Browsers and PDF apps often ask on first launch or after an update, and agreeing replaces your Change All choice. Decline the prompt, or set the default again with the steps above.

Our take

The default PDF app is one of the few settings on a Mac other apps are allowed to ask for, so it drifts. A browser is a poor default for documents you need to sign, fill or search. Pick the app you actually work in, and say no when the next one asks.

Simply PDF as the default

Reading is free in Simply PDF, with search, page thumbnails and dark mode, so it can be your everyday PDF app. Choose it under Open with and click Change All. If you mostly need Preview's tools, what Preview can do for free is a good place to start.

Questions

How do I make Preview open PDFs by default?

Select a PDF in Finder, press Command I, pick Preview under Open with and click Change All.

Why do my PDFs open in Chrome?

Chrome was chosen as the default PDF app, often by agreeing to its prompt. Change it in Get Info with Change All.

Why does my default PDF viewer keep changing?

An app asked to become the default and the prompt was accepted, often after an install or update. Decline those prompts and set it again in Get Info.

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