How to Crop an Image in Mac OS X with Preview

Cropping is an essential image editing function, helping to improve composition of a photo, to emphasize the focus of an image, or to reduce unnecessary parts of a picture. While many Mac users use third party tools to perform image cropping, no additional apps are needed to perform the task in OS X, because the bundled and under-appreciated Preview tool has crop functionality built right in to its editing toolset.

To try this yourself, you’ll want to have an image handy that you can crop down, and just about any version of Mac OS X. The rest of the process is very simple and can be done quite fast, particularly once you learn how to use the tools and master some keyboard shortcuts.

Cropping a Picture with Preview in Mac OS X

1. Open the image file you want to crop into the Preview app in Mac OS X
2. Click the “Editor Toolbar” button, it’s located on the right side of the general image toolbar and looks like a toolbox or a little pencil



3. Now choose the “Rectangular Selection” tool, it’s usually set by default but you can double-check this by choosing it from the left-most pulldown menu of the Editor Toolbar



4. Draw the desired rectangle on the image to the region of the picture you wish to crop



5. Press Command + K keys to crop the picture, or go to the “Tools” menu and click the “Crop” option to complete the crop, the image will immediately crop down to the section that was drawn within the rectangular selector tool
6. Go to the “File” menu and choose “Save” or “Save As” as desired to save the cropped version of the image

See, that was easy right? You now have a cropped image. You can draw the rectangular selector to whatever size you want and the crop function will take care of the rest.

The video walkthrough below demonstrates cropping an image from this wallpaper post:

Remember that by doing this you’re also indirectly resizing an image by reducing the total amount of pixels contained in the image file, but unlike the bulk resize functions you can not crop in a similar bulk fashion with groups of images in Preview because it requires a unique selection.

Cropping Images Faster in Preview with Keyboard Shortcuts

You can even speed up the cropping process by using keyboard shortcuts throughout the task, here is basically the same process as started from the Finder. This is an efficient trick to use if you plan on using the crop function often and want to speed things up:

1. Select the image to crop in the Finder then hit Command+O to open it in Preview (assuming Preview is the default image viewer application)
2. The selector tool should be immediately active and visible by default with a picture open, so draw the rectangular selection around the region to crop down as usual
3. Now hit Command+K to crop the image
4. Finally, hit Command+S to save the cropped picture

Memorizing the simple keyboard shortcuts used in this task can make the cropping process extremely fast, and combined with the general speed and efficiency of Preview app it’s usually much faster to go this route than opening images in Photoshop or Pixelmator.

The Preview app of OS X includes a myriad of image editing functions, markup tools, and conversion functions that are largely overlooked and underused, so if you’re just learning to use the Preview app for simple photo modifications and editing, crop is a great place to start.

Of course this is limited to the Mac, but for users on the mobile side of things there is no Preview application to be found on the iPhone or iPad, so instead users can find the Photos app supports cropping photos in iOS very easily with a similar selector tool, or use third party tools as well.