Set Preview as your default image viewer in System Settings

To make Preview the default app for opening images on your Mac, go to System Settings (the gear icon in your dock or Applications folder), then select Default Apps from the sidebar. Scroll down until you find image file types — you'll see entries like JPEG, PNG, HEIC, and others. Click the dropdown next to each image format you want to open with Preview, then select Preview from the list.

You only need to change the formats you actually use. If you never open TIFF files, for example, you can leave that one alone. Most people just need to set JPEG and PNG, which cover the vast majority of images you'll encounter online and in email.

After you've made your changes, close System Settings. The next time you double-click an image file of that type, it will open in Preview instead of whatever app was handling it before.

Key Takeaways

  • Open System Settings, select Default Apps, and find the image file types you want to change.
  • Click the dropdown next to each image format and choose Preview from the list.
  • You can set different defaults for different image types — for example, JPEG in Preview but PNG in another app.
  • Changes take effect immediately; the next time you open an image file, it will use your new default.
  • If Preview doesn't appear in the dropdown, make sure Preview is installed in your Applications folder.

Why Preview instead of other image apps

Preview comes built into every Mac and opens images instantly without needing to install anything extra. It handles the most common image formats — JPEG, PNG, HEIC, TIFF, GIF — and lets you do basic edits like cropping, rotating, and annotating without leaving the app.

If you use a different image editor like Photoshop or Pixelmator for serious work, you might want to keep Preview as your default for quick viewing and reserve the other app for when you actually need to edit. This way, opening a photo from email or a folder doesn't launch your heavy-duty editor every time.

Preview also handles PDFs, which means you can set it as your default for both images and documents if you prefer a single app for viewing both. This reduces the number of apps running in the background and keeps your workflow simpler.

What happens if Preview isn't in the dropdown

If you don't see Preview listed when you click the dropdown for an image type, it usually means Preview isn't in your Applications folder. This is rare on a fresh Mac, but it can happen if someone manually deleted it or if you're using a very old version of macOS.

To restore Preview, you can reinstall macOS without erasing your files. Go to System Settings > General > Software Update, then look for any available updates. If that doesn't help, you can download macOS from the App Store and run the installer, which will restore system apps like Preview.

You can also check whether Preview still exists by opening Finder, clicking Applications in the sidebar, and looking for the Preview icon. If it's there but not showing in the Default Apps dropdown, try restarting your Mac — sometimes the system needs to refresh its list of available apps.

Changing defaults for specific files instead of all images

If you want to open just one image file with Preview without changing your system default, right-click the file and select Open With, then choose Preview. This opens that single file in Preview without affecting what app opens similar files in the future.

You can also hold down the Option key while right-clicking to see Always Open With, which lets you set a different default for just that one file — useful if you have a PNG that you always want to open in a different app but want most PNGs to open in Preview.

Reverting to a different default later

If you change your mind and want a different app to open images by default, the process is identical. Go back to System Settings > Default Apps, find the image format, and click the dropdown to choose a different app. You can switch back and forth as many times as you want.

If you want to return to whatever app was handling images before you made this change, that app should still be in the dropdown list. Select it and you're back to your previous setup. There's no penalty for changing your defaults repeatedly, so you can experiment to find what works best for your workflow.

Frequently Asked Questions

Can I set Preview as default for some image types but not others?

Yes. Each image format has its own dropdown in Default Apps, so you can set JPEG to open in Preview, PNG to open in a different app, and HEIC in yet another. This is useful if you work with different formats for different purposes.

Will changing the default affect images I've already opened?

No. The default only controls what happens when you open a file going forward. Files you've already opened in another app won't switch apps. The change takes effect the next time you double-click an image file.

What if I want to open an image in a different app just one time?

Right-click the image file, select Open With, and choose the app you want. This opens that single file without changing your system default. The next image you open will still use your default app.

Does Preview handle all image formats?

Preview handles the most common ones — JPEG, PNG, HEIC, TIFF, GIF, and PDF. Some specialized formats like RAW camera files or WebP may not open in Preview. If you work with those formats, you might want to set a different default for them.

Can I set Preview as default for PDFs too?

Yes. PDFs appear in the Default Apps list just like image formats do. You can set Preview as your default for PDFs, or keep a different app like Adobe Reader if you need more advanced PDF tools.