How to Resize an Image on Mac

This article explains how to change the size of an image on a Mac using the Pages and Preview apps.

How Do I Resize an Image?

The most direct way to resize an image on a Mac is through Preview, the default image viewing app. It’s not ideal for more complex image adjustments, but it’s a quick and easy way for something like resizing. Preview can open and adjust almost any standard image file, such as .JPEG, .JPG, .TIFF, .PNG, etc.

1. Open the image file in Preview.
   

   

2. Select Tools from the menu bar at the top of the screen, and then select Adjust Size.
   

   

3. This will pull up the Image Dimensions menu with an assortment of different options.
   

   

4. You can change the measurement type by clicking the pulldown menu on the right, which should show pixels by default.
   

   

5. Depending on the measurement type you need or are familiar with, you can select pixels, percent, inches, cm (centimeters), mm (millimeters), or points.
   

6. Typing in a new value in either the Width box will change the dimensions of the image’s width, and Height will change the height.
   

   

7. If Scale proportionally is checked off you only have to change the values in one of the two boxes as the other one will change automatically to fit.
   

   

8. Click OK to finish resizing your image. If everything looks good don’t forget to save when you’re finished!
   

   

How Do I Resize a JPEG Image?

You can also use Preview to resize a JPEG image on your Mac by following the same steps as above.

1. Open the .JPEG in Preview.
   

   

2. Select Tools > Adjust Size to pull up the Image Dimensions menu.
   

   

3. Typing in a new value in the Width box will change the dimensions of the image’s width, and Height will change the height.
   

   

4. If Scale proportionally is checked off you only have to change the values in one of the two boxes as the other one will change automatically to fit.
   

   

5. Click OK to finish resizing your image.
   

   

How Do I Change the Size of an Image in Pages on Mac?

Resizing an image in Pages is almost as straightforward as in Preview, though the menus and possible methods are notably different.

1. Click the image in your Pages document and select the Arrange tab in the menu column on the right-hand side.
   

   

2. Scroll down to the Size portion of the menu.
   

   

3. Enter a new value in either the Width and Height box and press return.
   

   

4. If Constrain proportions is checked off, you only have to change the value of Width or Height (not both) to change the overall dimensions of the image.
   

   

5. Alternately, you can manually resize the image with your mouse or trackpad until it fits the document the way you want it to.
   

6. With the image selected, move your cursor to one of the small white boxes displayed on any of the corners or sides. The cursor should change from a single arrow to a double-sided arrow.
   

7. When the double-sided arrow appears, click and drag the edge of the image to make it larger or smaller.
   

   

8. If Constrain proportions is checked off the image will resize while automatically retaining the same proportions (i.e. it won’t “stretch” out of proportion while you resize it).