How to Resize Images on Mac Using Photos or Preview

By | April 27, 2022

If you want to resize an image on your Mac, you don’t need an expensive app to do it. Luckily, macOS gives you some built-in tools that you can use to easily resize images.

Here’s how to quickly resize images on a Mac using Preview, Photos, ColorSync Utility, and even the Mail app.

Resize Using Preview

Preview is a powerful application that you can use for all kinds of tasks like viewing images, reading documents, and even signing PDFs. One of the most useful features is the ability to resize images, which is a simple Preview task.

Preview doesn’t require you to first import the image into the library, and it lets you open up the aspect ratio so you can stretch or squeeze the image if you want. For that reason, Preview is the best choice when it comes to resizing jobs for images other than those in your Photos library.

To resize an image with Preview:

  • Double-click on your image to open it with Preview, if that is your default image viewer. You can also select multiple images in the Finder, right-click, and select Open With > Preview.
  • Click Tools > Adjust Size from the menu bar.
  • use Fit into to specify a preset value or enter width and height yourself into the box provided.
  • Select the dropdown box to choose from pixels, percent, inches, or other units.
  • Optionally, you can check the box Scale proportionally to maintain the aspect ratio.
  • Press OK when you’re done.

You can then save the resized image using File > Save or Save As (by holding down the button Options). Or, you can click File > Export to determine the file format and image quality. Check out our tutorials How to Edit Photos on Mac Using the Preview App.

Resize Image Using Photos

Apple replaced iPhoto with the new Photos app in 2015. Today, most people are more familiar with the Photos app than its predecessor. As it turns out, you can use Photos for more than viewing your pictures. It lets you edit RAW photos, import your own custom filters, and even create slideshows.

You must import images into your library before you can edit them in Photos. Pictures you added from your iPhone, digital camera, or SD card should already be in your library. If you have images from the web or other sources, you can drag them to the Photos window or click File> Import from the menu bar.

From there, here’s how to resize images in Photos:

  • open Photos and select your image.
  • Click File > Export 1 Photo (or however much you resize).
  • Under Size You can choose preset Full Size, Large, Medium, or Small. Custom allows you to set your own size (in pixels).
  • choose Custom to determine Width or Height maximum, or select Dimension to limit the width and height for the amount you provide.
  • Optionally, you can select the file type, compression quality, whether to remove the embedded location information, and choose a color profile if you prefer.
  • Click Export and select where you want to save the image.
Notes: You also have the option to Export Unmodified Original, which you should choose if you’re printing images or plan to work with them in an external photo editor like Photoshop or Pixelmator. See also our article Best Free and Paid Image Editor For Mac.

Resize Image Using ColorSync Utility

ColorSync Utility is one of the default Mac app that you may not even know existed. Its purpose is to help you control the color profiles smoothly on your system. But you can also use this hidden gem to quickly resize images.

One thing to note about using the ColorSync Utility to resize images: images resized in this way must maintain their aspect ratio. To start:

  • Select an image in the Finder, right-click, and select Open With > ColorSync Utility.
  • At the top of the window, click the button Adjust Image Size.
  • Choose scale, width, or height in the dropdown Resize and enter a value in the box.
  • You can customize settings Quality and DPI Set optionally.
  • Click Apply.

You can then click File from the menu bar and select Save, Save As, or Export to save the resized image.

Resize Image Using Mail

If you want to resize an image on your Mac just to attach it to an email, you can actually resize the image in the Mail app itself:

  • Open the app Mail to the email you created.
  • Attach an image by dragging it into the email body or by clicking the button Attach in the toolbar to find and insert images.
  • With the image still selected in your email, click the dropdown box Image Size and choose a different size. You can choose from Small, Medium, Large, or of course, the actual size.
  • Finish composing the email and send it when you’re ready.

While you can’t resize pictures in Mail to a specific size, if you just want to resize them so they’re smaller for email messages, then this is convenient.

For Legacy OS X Users: Resize Images Using iPhoto

If you’re using an older Mac that’s not compatible with the latest version of macOS, there’s a good chance that you still have iPhoto. So for you old Mac users, here’s how to resize your images with iPhoto.

To resize an image with iPhoto, it must be in your iPhoto library. If you use iPhoto to import your pictures from your iPhone or digital camera, then this is already done. If you’re taking pictures from the web, the best way to import them is to drag them into the iPhoto window.

Once you have the images in your library, you can export and resize them to your liking. iPhoto will maintain the image’s aspect ratio, so you can’t stretch the image unnaturally. Resize by following these steps:

  • open iPhoto and select your image.
  • Click File > Export.
  • Under Size you can choose Full Size, Large, Medium or Small. Custom allows you to set your own size (in pixels).
  • choose Custom to determine Width or Height maximum, or select Dimension to limit the width and height for the amount you provide.
  • Press Export and select a location to save the image.

You can also select the file type, compression quality, regardless or not stripping location information, and set a prefix file name. The latter is useful for exporting a series of images that follow naming conventions.

Resize Image With Less Effort on Mac

This built-in app gets the job done when you want to resize an image on a Mac. Whichever way you decide it all depends on which one is more comfortable for you.