How to Batch Convert Images Using macOS Preview

by

There 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.

  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.

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

  5. Select File -> Export Selected Images... from the menu bar.

  6. Choose a location to export your converted images.

  7. Click the Options button in the Export window.

  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.

  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

(View all)
Avatar
25 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)
Avatar
25 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?)

[USER=3]@MacRumors[/USER]: could you guys at least tag these all with "Hints" or something?
Score: 3 Votes (Like | Disagree)
Avatar
25 months ago
These How-To articles are the best of MacRumors.
Score: 3 Votes (Like | Disagree)
Avatar
25 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)
Avatar
25 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)
Avatar
25 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)

Top Stories

Hands-On With iOS 14 Widgets, Custom Icons, and Home Screen Setup

Tuesday September 22, 2020 3:25 pm PDT by
Apple with iOS 14 introduced widgets on the Home Screen, leading to unprecedented levels of customization for the iPhone. Combined with Shortcuts that let you change an app's icon, iOS 14 lets you create a whole new look for your Home Screen. Subscribe to the MacRumors YouTube channel for more videos. We've been following along with some of the creative alternative Home Screen designs that M...

New Images Leak of iPhone 12 Braided USB-C to Lightning Cable

Thursday September 24, 2020 2:37 am PDT by
Rumors suggest Apple's upcoming iPhone 12 models will ship with a new Lightning to USB-C cable that includes a braided fabric design. Images of the purported cables were leaked in July, and today leaker Mr White has shared new images that give us a closer look at what we might get included in the iPhone 12 box. The photos show a USB-C to Lightning cable with a clearly braided design rather...

Apple's iPhone 12 Event Could Happen on October 13 Based on Rumors From Mobile Operators

Wednesday September 23, 2020 11:51 am PDT by
Apple's upcoming iPhone-centric event could perhaps be held on Tuesday, October 13, according to information shared with MacRumors by an employee at a UK cellular carrier. There's no way for us to confirm the dates at this point in time nor are we sure on the credibility of the source, but even without a rumor, Tuesday, October 13 is a good guess based on Apple's historic launch timelines, ...

New Version of Microsoft Office Coming Next Year That Won't Require a Subscription

Thursday September 24, 2020 1:53 am PDT by
Microsoft will next year offer a new perpetual release of Microsoft Office for Mac and Windows that doesn't require a subscription to use, according to the software giant (via Windows Central). "Microsoft Office will also see a new perpetual release for both Windows and Mac, in the second half of 2021," said Microsoft in a blog post announcing the next version of its Exchange server,...

Interest in iOS 14 Home Screen Ideas Helps Pinterest Break Daily Download Record

Wednesday September 23, 2020 4:37 am PDT by
Apple's introduction of widgets on the Home Screen in iOS 14 has driven a surge in interest among users looking to customize their iPhone, and that has reportedly had a knock-on effect for Pinterest, whose iOS app has seen record downloads as users flock to its content seeking design inspiration. As reported by TechCrunch, App Store intelligence firm Apptopia was first to note the impact of ...

'iPhone 12 mini' Name Reappears in Leaked Apple iPhone 12 Case Stickers

Friday September 25, 2020 1:58 am PDT by
Earlier this week a proven leaker claimed that the iPhone 12 lineup would be named "iPhone 12 mini," "iPhone 12," "iPhone 12 Pro," and "iPhone 12 Pro Max," and today the same nomenclature has appeared again in a photo depicting alleged stickers from unreleased Silicone iPhone cases originating from Apple's international distribution center in Ireland. The photo shows three stickers with the...

Apple Releases iOS 14.0.1 With Fix for Bug That Resets Default Apps After Rebooting

Thursday September 24, 2020 10:12 am PDT by
Apple today released iOS 14.0.1, the first update to the iOS 14 operating system that was released on September 16. Today's update is a bug fix update addressing issues that weren't able to be fixed in the initial iOS 14 launch. The iOS 14.0.1 update is available on all eligible devices over-the-air in the Settings app. To access the new software, go to Settings > General > Software Update. ...

Apple Emphasizes That Solo Loop May Increase in Length Over Time, Updates Sizing Guide With More Specific Instructions

Wednesday September 23, 2020 8:26 am PDT by
Apple on Tuesday updated one of its support documents to emphasize that the new silicone rubber Solo Loop for the Apple Watch may increase in length over time, as mentioned in fine print at the bottom of the Solo Loop product page. Apple has also updated its printable Solo Loop sizing guide with more specific instructions, as noted by 9to5Mac's Michael Steeber. The guide now advises users to ...

iOS 14 Widgets Offer iPhone Users Creative Home Screen Ideas

Sunday September 20, 2020 8:43 pm PDT by
Updated on September 22nd with hands on video. In iOS 14, Apple introduced ‌the concept of Home Screen‌ widgets, which provide information from apps at a glance. Widgets can be pinned to the Home Screen in various spots and sizes, allowing for many different layouts. Despite the relative lack of...

Kuo: Mini-LED Displays to Debut in Apple's Next iPad Pro

Tuesday September 22, 2020 11:45 pm PDT by
Following his report earlier this week indicating that Apple will be accelerating adoption of mini-LED displays in its iPad and Mac notebook lineups thanks to better than expected development from potential secondary supplier Sanan Optoelectronics, analyst Ming-Chi has released a new report today sharing a bit more perspective on the mini-LED display market as it relates to Apple. Kuo says...