How to change your default PDF viewer
Your default PDF viewer is the program that opens when you double-click a PDF file. You can change it in your operating system's settings without uninstalling anything — the old viewer stays on your computer, it just stops opening PDFs automatically. The steps differ slightly depending on whether you use Windows, Mac, or Linux, but the principle is the same: you tell your system which program you prefer.
Most people stick with whatever came pre-installed, but you might want to switch if the default viewer is slow, lacks features you need, or crashes often. Common alternatives include Adobe Acrobat Reader, Foxit Reader, SumatraPDF, and Preview (on Mac). You can test a different viewer by right-clicking a PDF and choosing "Open with" before you make it the permanent default.
Key Takeaways
- On Windows 10 and 11, go to Settings > Apps > Default apps, search for .pdf, and select your preferred viewer from the list.
- On Mac, right-click any PDF, choose "Open With," select your viewer, then click "Change All" to make it the default for all PDFs.
- On Linux, the method depends on your desktop environment, but GNOME and KDE both let you set defaults through file properties or system settings.
- You do not need to uninstall your old viewer — changing the default just tells your system which one to use when you open a PDF normally.
- If a program does not appear in the default list, you may need to install it first or manually browse to its executable file.
Changing your default PDF viewer on Windows 10 and 11
Open Settings by pressing the Windows key and typing "settings," then click the Settings app. Navigate to Apps in the left sidebar, then click Default apps. In the search box at the top, type ".pdf" — this searches for file type associations rather than program names.
When you search for .pdf, you will see a list of programs that can open PDF files. Click on the current default (usually Microsoft Edge or Adobe Acrobat Reader), and a menu will appear showing all installed PDF viewers on your computer. Select the one you want and click it. The change takes effect immediately — the next time you double-click a PDF, it will open in your new default viewer.
If the viewer you want does not appear in the list, the program may not be installed yet, or it may not have registered itself with Windows. Install the program first, then return to Settings and search for .pdf again. If it still does not appear, you can click "Choose a default" at the bottom of the list and manually browse to the program's executable file (usually in Program Files or Program Files (x86)).
Changing your default PDF viewer on Mac
On Mac, the process is faster. Open Finder and locate any PDF file on your computer. Right-click the PDF and select "Open With" — this shows all programs that can open PDFs. Choose the viewer you want to use.
After you select a viewer, a dialog box appears asking if you want to change the default for all PDF documents. Click "Change All" to make this your permanent default. From that point forward, all PDFs will open in your chosen viewer when you double-click them. If you want to switch back later, repeat the same process with a different viewer.
If your preferred viewer does not appear in the "Open With" menu, the program may not be installed. Download and install it first, then return to Finder and try again. Mac automatically detects programs that can handle PDFs once they are installed.
Changing your default PDF viewer on Linux
Linux distributions vary, but most use one of two desktop environments: GNOME or KDE. On GNOME (used by Ubuntu, Fedora, and others), right-click a PDF file in your file manager and select Properties. Click the "Open With" tab, choose your preferred viewer from the list, and click "Set as default." The change applies immediately.
On KDE (used by Kubuntu, openSUSE, and others), right-click a PDF and select Properties. Go to the General tab, click the button next to "Opens with," select your viewer, and click OK. Some KDE systems also let you set defaults through System Settings > Applications > File Associations, where you can search for PDF and choose your viewer from there.
If your preferred viewer does not appear in the list on either desktop environment, install it through your distribution's package manager first. For example, on Ubuntu you might run sudo apt install evince or sudo apt install okular in the terminal. After installation, the viewer will appear in the "Open With" menu.
What to do if your preferred viewer is not in the list
Some programs, especially older or less common PDF viewers, do not automatically register with your operating system. If you have installed a viewer but it does not appear in your default apps list, try these steps.
On Windows, click "Choose a default" at the bottom of the .pdf search results in Settings. A file browser will open — navigate to Program Files or Program Files (x86), find the folder for your PDF viewer, and select its executable file (usually named something like "viewer.exe" or the program name with .exe). Click Open, and Windows will add it to the list.
On Mac and Linux, the viewer should appear automatically once installed. If it does not, try opening the PDF directly from the program itself (File > Open) to ensure the program is working. Then try the "Open With" method again — sometimes the system needs a moment to detect newly installed programs.
Testing a new viewer before making it the default
Before you commit to a new default, test it on a few PDFs to make sure it works the way you expect. Right-click a PDF, select "Open With," and choose a viewer without clicking "Change All" or "Set as default." This opens the PDF in that viewer just once, without changing your system settings.
Pay attention to how fast it opens, whether it displays text and images clearly, and whether any features you use (like annotations, form filling, or bookmarks) work properly. If you like it, go back and make it your default using the steps above. If not, try another viewer. This approach saves you from having to undo a change if the new viewer does not meet your needs.
Common PDF viewers and what they offer
Adobe Acrobat Reader is the most widely used PDF viewer and comes pre-installed on many computers. It handles all standard PDF features and is reliable, though some users find it slower than alternatives. It is free to download and works on Windows, Mac, and Linux.
Microsoft Edge (Windows 11) and Preview (Mac) are lightweight built-in options that open PDFs quickly. They lack advanced features like form filling or annotations, but they are fast and use less memory than heavier programs.
Foxit Reader is a faster alternative to Adobe Reader with a smaller file size. It supports annotations and form filling and is available for Windows and Mac. SumatraPDF is a minimal, fast viewer for Windows only. Okular (Linux) and Evince (Linux) are lightweight options built for GNOME and KDE desktops.
Frequently Asked Questions
Can I set different default viewers for different types of PDFs?
No — your operating system applies one default to all PDF files. However, you can always right-click a specific PDF and choose "Open With" to open it in a different viewer without changing the system default. Some advanced users on Linux can create custom file associations, but this requires terminal commands and is not supported through graphical settings on Windows or Mac.
Will changing my default PDF viewer affect PDFs that open inside web browsers?
Usually not. When you click a PDF link in a web browser, most browsers open the PDF in their own built-in viewer or a browser extension, not your system default. If you want PDFs to open in your chosen viewer instead, you may need to change settings within the browser itself — this varies by browser and is separate from your system default.
What if I accidentally set the wrong program as my default and now PDFs won't open?
Go back to your default apps settings and search for .pdf again. You should see the program you selected, even if it is not working properly. Click it and choose a different viewer from the list. If no viewers appear at all, you may need to reinstall a PDF viewer like Adobe Acrobat Reader or Foxit Reader before you can set a new default.
Do I need to uninstall my old PDF viewer when I switch to a new one?
No. Changing the default just tells your system which program to use when you double-click a PDF. Your old viewer remains installed and you can still open it manually if you need it. Uninstalling is optional and only necessary if you want to free up disk space or remove a program you no longer use.
Why does my PDF viewer keep changing back to the default after I change it?
Some programs, especially web browsers and security software, automatically reset themselves as the default PDF handler when they update. If this happens repeatedly, check whether any recently updated programs have settings that control PDF handling. You can also try disabling automatic updates temporarily while you test your preferred viewer, though this is not recommended for security reasons.