Batch Image Conversion in Mac OS X the Easy Way with Preview

Jan 16, 2013 - 6 Comments

Preview in Mac Preview is a greatly under-appreciated app that has been bundled along with Mac OS X since the beginning, getting better and better with each OS X release. One quiet feature that has been around for a while is the ability to mass convert a group of pictures from one file type to another, often referred to as batch conversion. This lets you easily take a large amount of JPG files and convert them over to PNG, for example.

Batch image conversion works with any number of image files and with nearly any image formats. It’s safe to assume that if you can open the image files into Preview app, you can export them to a new file type, including GIF, ICNS, JPEG, JPEG-2000, BMP, Microsoft Icon, OpenEXR, PDF, Photoshop PSD, PNG, SGI, TGA, and TIFF.

How to Convert a Group of Image Files to a New Format with Preview

Converting large groups of image files this way is really easy in OS X, here is what you’ll want to do:

  1. From the Finder, select a group of images and open them all with Preview, do this either by launching the image files directly or dragging and dropping them into the Preview Dock icon
  2. Once the images are opened in Preview, click within the preview pane on the left side and then Select All, either by hitting Command+A or by pulling down the edit menu and choosing that option – you must select all the images to convert
  3. Pull down the File menu and choose “Export Selected Images…”
  4. Batch convert image file formats in Mac OS X with Preview

  5. Optionally, create a new folder for the converted pictures to save to, otherwise simply select the destination for the files to save to
  6. Now select the desired image format to batch convert all the selected image files to (you can Option-click to reveal more)
  7. Click “Choose” to save and begin the conversion process
  8. Set the destination and file format for converted image files to convert to, then start converting in Preview for Mac OS X

A progress indicator bar will appear over the pictures letting you know things are progressing:

Batch converting images in Preview on Mac OS X

Depending on the amount of images selected to convert, their resolutions – which can also be resized at the same time if desired, and their file formats, this process can either be very fast or somewhat time consuming. Batch conversion of image files is usually quite speedy, but it ultimately depends on the size of the image files, the formats chosen, and the speed of the Mac.

As mentioned, the Bulk Export Images feature in Preview is supported in all versions of OS X, including OS X Yosemite, OS X Mavericks, Mountain Lion, you name it. The interface may look a tiny bit different depending on the version of system software on the Mac.

Batch convert image files in Mac OS X with Preview

The video below walks through the group file type conversion process with Preview, taking a selection of JPG files and saving them to a new folder as PNG’s. As you may notice in the video, the original JPG files remain intact throughout this process.

The ability to convert a single image file has been around for quite some time and that shouldn’t be a mystery to those who have used Preview before, but the group conversion ability is limited to newer versions of the app in OS X.

If you follow us here at OSXDaily with regularity, you probably know that we recently showed how to perform image conversions from the command line using the sips tool as well, but using the GUI and Preview is much easier for most users and is going to have a wider appeal.

Enjoy this tip? Subscribe to the OSXDaily newsletter to get more of our great Apple tips, tricks, and important news delivered to your inbox! Enter your email address below:

Related articles:

Posted by: William Pearson in Mac OS X, Tips & Tricks

6 Comments

» Comments RSS Feed

  1. parakeet says:

    Preview is good but it needs some paint tools

  2. Connor says:

    I think you can also do this in adobe bridge?

  3. Janie Mac says:

    Am I misreading this?
    I can’t export as GIF from Preview ever since upgrading to Mountain Lion. It used export to GIF in Snow Leopard, but your article leads me to believe I should still be able to export a GIF.

    Only choice I have for export are:
    JPEG
    JPEG-2000
    OpenEXR
    PDF
    PNG
    TIFF

    Where is my GIF option gone?

  4. mike sanders says:

    why can’t I view your video in my email, it is just a black rectangle. OS X 10.8.3
    It has been this way for some time.

  5. James says:

    Thanks for this simple and extremely useful trick. Time to shrink the massive library now!

Leave a Reply

 

Shop for Apple & Mac Deals on Amazon.com

Subscribe to OSXDaily

Subscribe to RSS Subscribe to Twitter Feed Follow on Facebook Subscribe to eMail Updates