Preview appThere are many third-party apps available for Mac that will batch convert images for you (Permute is one example). And then there's Preview, the powerful file viewer that's built into macOS.

Preview will happily convert several images for you in one go. If you have lots of photos on your Mac in Apple's HEIC format, for instance, you can use Preview to quickly convert them to the more accessible JPEG format.

In fact, what's not obvious to many users is that Preview is capable of converting files in 18 different image formats, including the following:

  • GIF
  • HEIC
  • ICNS
  • JPEG
  • JEPG-2000
  • KTX
  • Microsoft BMP
  • Microsoft Icon
  • OpenEXR
  • PBM/PGM/PPM
  • PDF
  • PNG
  • PVRTC
  • Photoshop
  • PostScript
  • QuickTime Movie
  • TGA
  • TIFF

The secret to accessing all of the available format export options in Preview is with the Option (⌥) key. Keep reading to learn how it's done.

How to Batch Convert Images in Preview

  1. In a Finder window, hold down the Command (⌘) key and individually click all the images you want to convert; if they're grouped together consecutively, hold down Shift and click the first and then the last file, and all of them will be selected.
    how to batch convert images in preview03

  2. Double-click one of the selected images to open them all in Preview. If Preview isn't your default image viewer, right-click (Ctrl-click) instead and choose Open With -> Preview from the dropdown menu.
  3. Click inside the Preview sidebar. (if it's not showing, click the View Menu button and select Thumbnails.) Alternatively, if you're using the Contact Sheet view, drag a box over all the images to select them.
    batch convert images in Preview

  4. Select Edit -> Select All from the Preview menu bar, or use the Command-A keyboard shortcut to select all the open images.
    how to batch convert images in preview 03

  5. Select File -> Export Selected Images... from the menu bar.
    how to batch convert images in preview02

  6. Choose a location to export your converted images.
    how to batch convert images in preview 08

  7. Click the Options button in the Export window.
    how to batch convert images in preview04

  8. Drag the Quality slider to the desired level (keep an eye on the file size).
  9. Select an image type from the Format dropdown. Pro tip: Hold down the Option (⌥) key when you click the Format button to reveal several more image formats available to you.
    how to batch convert images in preview05

  10. Click Choose.

A progress indicator bar will replace Preview's Export window. Once it has completed you'll find your exported images in the chosen location and format, ready for use in your projects.

Note that you can also batch resize images using the method outlined above. After Step 4, select Tools -> Adjust Size... from the menu bar, input the resolution you want all the selected images to take, and click Resize. Note: You may need to select all the images again for export.

Tag: Preview

Top Rated Comments

fairuz Avatar
58 months ago
Preview is one of those secretly really powerful Mac apps for which there's no good replacement elsewhere. At least not that I've seen.
Score: 3 Votes (Like | Disagree)
ignatius345 Avatar
58 months ago
These How-To articles are the best of MacRumors.
Agreed. I would totally visit a MacRumors spinoff site... MacHints (or maybe something catchier?)

@MacRumors: could you guys at least tag these all with "Hints" or something?
Score: 3 Votes (Like | Disagree)
Solomani Avatar
58 months ago
These How-To articles are the best of MacRumors.
Score: 3 Votes (Like | Disagree)
AlumaMac Avatar
58 months ago
If anyone can tell me how to access all of Preview's format conversion options in Automator, I'd be very grateful.

Looks like Automator hasn't been updated and I doubt it will. You could add a terminal command to your Automator Workflow that runs the 'sips' command to do additional filetype conversions. (i.e. sips -s format jpeg filename.gif --out newfilename.jpg)
Score: 2 Votes (Like | Disagree)
outskirtsofinfinity Avatar
58 months ago
How do you know which buttons have "hidden" features that are revealed using the Option button? Is there a GUI style convention (say, the way the button is shaded when you hover over it, or something?) that suggests that more hidden options are available? Or is it just impossible to tell and you have to try the Option button everywhere you go to try to reveal hidden treasure... i.e., is it considered more of an "easter egg" kind of thing to delight the ones that stumble across these treasures and allow them to write a 'macOS Secrets revealed' kind of book or article? It just seems so stupid... it's something I'd expect from some hopeless nerd Android programmer (or the self indulgent programmers of the Tesla user interface), not from Apple. E.g., how's my mother in law supposed to figure it out?
Score: 2 Votes (Like | Disagree)
Undecided Avatar
58 months ago
Is there a way to do file conversions like this that preserves the meta data (original image date, etc.)?
Score: 2 Votes (Like | Disagree)

Popular Stories

iPhone 15 Pro Buttons CAD Leak

iPhone 15 Pro Low-Energy Chip to Allow Solid-State Buttons to Work When Device is Off or Out of Battery

Wednesday March 29, 2023 1:54 am PDT by
The iPhone 15 Pro and Pro Max will use a new ultra-low energy microprocessor allowing certain features like the new capacitive solid-state buttons to remain functional even when the handset is powered off or the battery has run out, according to a source that shared details on the MacRumors forums. CAD-based render of new solid-state buttons on iPhone 15 Pro models The source of this rumor is ...
maxresdefault

Apple Announces WWDC 2023 Event Taking Place June 5 to 9

Wednesday March 29, 2023 9:58 am PDT by
Apple today announced that its 34th annual Worldwide Developers Conference will take place from Monday, June 5 to Friday, June 9. Like WWDC 2020, 2021, and 2022, WWDC 2023 will be an online event for the most part, and it will be open to all developers at no cost. Subscribe to the MacRumors YouTube channel for more videos. Apple will provide online sessions and labs, which will allow...
iPhone 15 Pro Multi Purpose button Mute Switch Feature Green 2

iPhone 15 Pro Rumored to Feature Multi-Use Action Button Instead of Mute Switch

Wednesday March 29, 2023 7:28 am PDT by
iPhone 15 Pro and iPhone 15 Pro Max models are rumored to feature a customizable Action button like the Apple Watch Ultra, according to a MacRumors forum member who leaked accurate details about the Dynamic Island on iPhone 14 Pro models last year. The source claimed the Action button will replace the Ring/Silent switch that has been included on every iPhone model since 2007. They did not...
iOS 16

Apple Releases iOS 16.4 With New Emoji, Safari Web Push Notifications, Beta Changes, Voice Isolation for Calls and More

Monday March 27, 2023 10:03 am PDT by
Apple today released iOS 16.4, the fourth major update to the iOS 16 operating system that initially came out last September. iOS 16.4 comes two months after the launch of iOS 16.3, an update that added Security Keys for Apple ID. iOS 16‌.4 and iPadOS 16.4 can be downloaded on eligible iPhones and iPads over-the-air by going to Settings > General > Software Update. It can take a few minutes...
Apple Music Classical

Apple Explains Why It Launched an iPhone App Dedicated to Classical Music

Monday March 27, 2023 8:54 pm PDT by
Apple today published a support document explaining why it decided to release a standalone Apple Music Classical app for classical music. In short, Apple says the app was designed to support classical music's complex metadata:Classical music is different. It has longer and more detailed titles, multiple artists for each work, and hundreds of recordings of well-known pieces. The Apple Music...
iOS 16

Apple Seeds First Betas of iOS 16.5 and iPadOS 16.5

Tuesday March 28, 2023 10:15 am PDT by
Apple today seeded the first betas of upcoming iOS 16.5 and iPadOS 16.5 updates to developers for testing purposes, with the software coming a day after the launch of iOS 16.4 and iPadOS 16.4. Registered developers can opt in to the betas by opening up the Settings app, going to Software Update, tapping on the "Beta Updates" option and toggling on the iOS 16 Developer Beta. Note that an...
home upgrade available feature

PSA: Apple Has Made Its New Home Architecture Update Available Again

Tuesday March 28, 2023 1:50 am PDT by
Apple has made the option to upgrade to new Home architecture available again with the release of iOS 16.4, iPadOS 16.4, and macOS Ventura 13.3, after it temporarily pulled the update in December. After updating Apple devices to the latest software, users can once again opt to upgrade any homes set up in the Home app to the new Home architecture, which Apple says brings faster, more reliable ...