Windows: Change the default app for a file type
When you double-click a PDF, image, or document, Windows opens it in whatever app you set as the default. You can change this in Settings without touching the file itself. The process is the same whether you want to open PDFs in a different reader, photos in a different viewer, or documents in a different editor.
Go to Settings > Apps > Default apps. Scroll down to find the file type you want to change — look for .pdf, .jpg, .docx, or whatever extension you're working with. Click on it, and Windows shows you the apps installed on your computer that can open that type of file. Select the one you want to use going forward.
If the app you want isn't listed, click Look for another app on this PC, navigate to the program's folder (usually in Program Files), and select its executable file — the one that ends in .exe. After you choose it, that app becomes the default for that file type.
Windows: Change the default app for a single file right now
You don't have to change the system default if you only want to open one file differently. Right-click the file, select Open with, and choose from the list. If you want to use an app that isn't shown, click Choose another app and find it in the full list.
This one-time choice doesn't affect what happens the next time you open a different file of the same type — it only applies to that single file in that moment.
Mac: Change the default app in Get Info
On a Mac, select the file you want to change, then press Command + I to open the Get Info window. Look for the section labeled Open with and click the dropdown menu. Select the app you want to use for this file type going forward.
After you choose, click Change All at the bottom of that section. This tells macOS to open all files of that type with the app you selected. If you only want to change this one file, don't click Change All — just close the window.
Mac: Change the default app in System Settings
For a more permanent change across your whole system, go to System Settings > General > Default apps. Find the file type in the list — you may need to scroll — and click on it to see which apps can open it. Select the one you want to use by default.
This method works well if you want to set one app as the default for multiple file types at once. For example, you can make a single PDF reader your default for all PDFs, all images, and all documents in one visit to Settings.
Key Takeaways
- On Windows, go to Settings > Apps > Default apps, find the file type, and select the app you want to use.
- On Mac, select a file, press Command + I, choose an app from the Open with dropdown, and click Change All to explore it to all files of that type.
- You can change the default for a single file without changing your system settings by right-clicking and selecting Open with.
- If the app you want isn't in the list, you can browse your computer to find its executable file and select it manually.
- Changing defaults does not affect files you've already opened — it only changes what happens when you open new files going forward.
Why you might want to change your defaults
Your operating system comes with built-in apps for common file types — Photos on Mac, Photos app on Windows, Notepad on Windows, TextEdit on Mac. These work fine for basic tasks, but they're often slower or less full-featured than alternatives you install yourself.
If you work with PDFs constantly, a dedicated PDF reader like Adobe Acrobat Reader or Foxit is faster than opening them in your web browser. If you edit photos, an image editor like Photoshop or GIMP gives you tools the built-in viewer doesn't have. If you write code, a text editor like Visual Studio Code or Sublime Text is built for that work in ways Notepad isn't.
Changing defaults saves you the step of right-clicking and choosing "Open with" every single time. It also means your files open in the app where you actually want to work on them, not in whatever came with your computer.
What happens if you change your mind
Changing a default is not permanent. You can change it back at any time by going through the same Settings menu and selecting a different app. There's no penalty or lock-in — Windows and Mac both let you switch as often as you want.
If you want to go back to what your computer came with, select the original app from the list. On Windows, that's usually Microsoft Edge for web files, Photos for images, and Notepad for text. On Mac, it's usually Safari for web files, Photos for images, and TextEdit for text.
Frequently Asked Questions
Can I set different defaults for the same file type?
No — your system can only have one default app per file type. However, you can always right-click a file and choose Open with to use a different app for that single file without changing your system default.
What if I uninstall an app that was set as my default?
Windows and Mac will automatically reset the default to another app that can open that file type. If no other app is installed, they'll use their built-in option. You won't get an error — the system handles it automatically.
Does changing the default app affect files I've already opened?
No. Changing your default only affects files you open after you make the change. Files you've already opened stay open in whatever app you used to open them.
Can I set a default app for a file that doesn't have an extension?
On Windows, files without extensions are harder to set defaults for — the system relies on the extension to know what type of file it is. On Mac, you can use Get Info on any file and set a default app regardless of whether it has an extension.
What if the app I want to use isn't showing up in the default apps list?
On Windows, click Look for another app on this PC and navigate to the program's installation folder, usually in Program Files. On Mac, if the app doesn't appear in the Open with dropdown, make sure it's installed and try restarting your computer.