How to resize images on a Mac

Six ways at a glance

Resize an image in Preview (built in)

1. Open the image in Preview, then choose Tools › Adjust Size.
2. Select Scale proportionally, so that the other side follows when you change one.
3. Enter a width or a height, or choose a size from the Fit into menu. For a percentage, choose percent next to the Width and Height fields.

Several images: open them in one Preview window, select them in the sidebar, then choose Tools › Adjust Size.

Steps from Apple’s Preview guide: Crop, resize, or rotate an image.

Good to know. Apple notes that changes to a Preview document are saved automatically, so duplicate the picture first if you want to keep the original (File › Duplicate in the Finder). Preview shows the resulting file size as you set the dimensions.

Resize photos in Photos (built in)

1. In Photos, select the photos.
2. Choose File › Export › Export Photos.
3. Click the arrow beside Photo Kind, then choose a Size.
4. Click Export and choose where to save them.

Your originals stay in your library.

Make an image smaller in the Finder (built in)

1. Control-click the image in the Finder.
2. Choose Quick Actions › Convert Image (under More on macOS 27).
3. Pick a format and a size.

Apple describes it as converting an image to another format or a smaller size.

Batch resize images with Automator (built in)

Build it once, and it sits in the Finder from then on.

1. Open Automator, choose File › New, select Quick Action, then click Choose.
2. Set Workflow receives current to Image files.
3. Add the Scale Images action. Automator offers to add Copy Finder Items, so that copies are changed and your originals are preserved: click Add, and choose where the copies go.
4. Set the size, then choose File › Save and give it a name.

To use it, select images in the Finder, Control-click, and choose it under Quick Actions.

Steps from Apple’s Automator guide: Use Quick Action workflows on Mac.

Good to know. Scale Images resizes by the longer side in pixels or by a percentage of the current size. Without Copy Finder Items, it changes the images you pass to it.

Resize an image in the Terminal

macOS includes sips. To fit a picture in 1200 pixels on its longer side, run:

sips -Z 1200 photo.jpg --out photo-1200.jpg

Our 2000 × 1332 test photo came out at 1200 × 799. We tried it on macOS 15.7.

The right-click way

Resize images with Ricly

1. Install Ricly and open it. Turn on the Finder extension when it asks (one setting), then create your free account and verify your email.
2. In Finder, select the pictures and right-click: choose Ricly › Quick Resize….
3. Pick a percentage, a width or a height, or a file size to stay under. Each copy lands next to its original.

• 25, 50 or 75 %, or a width or a height in pixels, and the other side follows the ratio.
• Under… a file size, from 500 KB to 10 MB or one you type: Ricly keeps the size in pixels if the file already fits at JPEG quality 0.85, and otherwise picks the largest size that does.
• Unlink width and height to fill a frame: Crop, framed on the subject when Ricly finds one, Fit, with margins, or Stretch.
• A PNG stays a PNG; everything else comes out as JPEG at quality 0.92, or 0.85 under a file size.
• The camera, lens, date and orientation are kept.
• Each copy is named after its new size, like Portrait_raw [1200x1500].jpg, and lands next to the original, which is never touched. Nothing is overwritten if the name is taken.
• Four images at a time, and no monthly limit.
• Everything happens on your Mac. Nothing is uploaded.

Where it falls short. HEIC, WebP, TIFF and BMP come out as JPEG. Scaling a small picture up makes it softer: the panel warns you first, and Upscale Image, a Pro tool in the same menu, is the one for a sharp enlargement. It needs macOS 13 or later.

Download for MacSend it to my Mac Free, no monthly limit · macOS 13 or later · Notarized by Apple

Resize an image to a file size

Forms often count in megabytes, not pixels. In Preview, the resulting file size shows as you change the dimensions, so you try a size and check. In Ricly, choose Under… and the limit, like 2 MB: it keeps the size in pixels if the file already fits, and otherwise writes the largest size that does, in one go.

Resize many images at once

In Ricly, open the folder, select the images (⌘A selects everything in the window) and right-click once: the menu reads Quick Resize (20 files), you set the size once, and every copy follows it, each named after its own new dimensions. Built in, you can select several images in Preview’s sidebar, in Photos or in the Finder, run an Automator Quick Action, or loop sips in a script.

Which one should you use?

Resizing images on a Mac: common questions

Quick Resize in Ricly →Compress images on a Mac →Strip Metadata →