Set a new default PDF opener in three steps

Your computer has a default program assigned to open PDF files — the one that launches automatically when you double-click a PDF. You can change this to any PDF reader you have installed, whether that's Adobe Acrobat Reader, Microsoft Edge, Preview on Mac, or another program. The steps differ slightly between Windows and Mac, but both take less than a minute.

The reason to change your default is usually speed or preference. Adobe Reader works everywhere but can be slow to launch. Edge opens instantly. Preview on Mac is lightweight. Some people prefer a reader with better annotation tools, or one that doesn't try to sell them a subscription. Whatever your reason, you control which program opens when you click a PDF.

Key Takeaways

  • On Windows, right-click any PDF file, select "Open with", then choose "Choose another app" and mark your preferred reader as the default.
  • On Mac, select any PDF file, go to File menu and choose "Get Info", then change the "Open with" dropdown and click "Change All".
  • You must have the new PDF reader already installed on your computer before you can set it as the default.
  • Changing the default does not uninstall your old reader — it just stops it from opening automatically when you click a PDF.
  • If you change your mind later, you can switch back to a different reader using the same steps.

How to change your default PDF opener on Windows

On Windows 10 and 11, the fastest way is through a PDF file itself. Find any PDF on your computer — in Downloads, Documents, or Desktop. Right-click it and select "Open with". A submenu appears showing programs that can open PDFs.

If you see the program you want in that list, click it once. Then a dialog box appears asking if you want to always use this program to open PDFs. Check the box that says "Always use this app to open PDF files" and click OK. You are done — from now on, that program opens when you double-click any PDF.

If you do not see your preferred reader in the "Open with" list, click "Choose another app" at the bottom. A longer list appears. Scroll down and find the program you want. Click it once to select it, check the box for "Always use this app", and click OK.

If your reader still does not appear, it may not be installed yet. Go to the program's website, download it, and run the installer. Then repeat these steps.

How to change your default PDF opener on Mac

On Mac, open Finder and locate any PDF file. Click it once to select it (do not open it). Then click the File menu at the top and select "Get Info". A window opens showing details about the file.

Look for the section labeled "Open with". Click the dropdown menu next to it. A list of programs that can open PDFs appears. Select the reader you want to use as your default.

After you choose a program, a button appears below the dropdown that says "Change All". Click it. Mac asks you to confirm. Click "Continue". From now on, all PDF files open with the program you selected.

If your preferred reader does not appear in the dropdown, make sure it is installed. Download it from the program's website, drag it into your Applications folder, and try again.

What to do if your preferred PDF reader is not installed

If the program you want to use does not appear in the list, you need to install it first. Common PDF readers include Microsoft Edge (built into Windows 10 and 11), Adobe Acrobat Reader (free download from adobe.com), and Preview (built into Mac). On Windows, you can also use Chrome or Firefox if you have them installed.

Go to the program's official website and download the installer. Run it and follow the on-screen instructions. Once installation is complete, go back to the steps above and set it as your default. The program should now appear in your list.

Why your default PDF opener might change on its own

Sometimes after you install a new program, it automatically sets itself as your default PDF opener without asking. This happens most often with Adobe Reader and some antivirus software. If this bothers you, simply follow the steps above to switch back to your preferred reader.

Windows updates can also reset your default apps. If you notice your PDFs suddenly open in a different program, use the steps above to change it back. Mac is more stable about this — it rarely changes your defaults without your action.

How to open a PDF in a different program one time only

You do not have to change your default to open a single PDF in a different program. Right-click the PDF file and select "Open with". Choose the program you want to use for that one file. Your default stays the same, and the next PDF you click will open in your usual reader.

On Mac, right-click the PDF, hover over "Open With", and select the program you want. Again, this opens only that one file in the different program — your default does not change.

Frequently Asked Questions

Does changing my default PDF opener delete the old program?

No. Changing your default only tells your computer which program to use when you double-click a PDF. The old program stays installed on your computer. You can still open it manually from your Applications folder or Start menu if you want to use it for something else.

Can I set different PDF readers as default for different folders?

No. Your default PDF opener applies to all PDF files on your computer. However, you can right-click any individual PDF and open it in a different program without changing your system default.

What if I set the wrong program as default by accident?

Just follow the same steps again and choose a different program. You can change your default as many times as you want. There is no limit to how often you can switch.

Will my default PDF opener change if I update Windows or Mac?

Windows updates sometimes reset your defaults, so you may need to set it again. Mac rarely does this. If you notice your PDFs opening in a different program after an update, use the steps above to set your preference again.

What if a PDF file opens in the wrong program and I cannot find "Open with" in the menu?

On Windows, make sure you right-clicked the PDF file itself, not a folder. On Mac, make sure you selected the PDF and then clicked the File menu at the very top of the screen. If the menu still does not appear, try restarting your computer and trying again.