Preview app on iMac not saving resized JPG images

Question

Level 1

26 points

Preview app on iMac not saving resized JPG images

I'm trying to edit a photo in the Preview app on an iMac. All I want to do is adjust the size of a JPG photo. Tools > Adjust Size... I uncheck Resample Image, change height, width and resolution. Click save, and close. When I reopen the photo, the original size comes back. I've tried numerous times with the same result. Even if I select File > Export... the same thing happens. This does NOT happen if I change the file type to TIFF. Is this normal behavior?

iMac M3

macOS 26.2

Preview Version 11.0 (1113.3.1)

Camera: Canon EOS R50

iMac 24″, macOS 26.2

Posted on Jan 27, 2026 1:13 PM

Reply

Answer 1

Top-ranking reply

brbo

Level 8

41,917 points

Feb 2, 2026 11:07 PM in response to pwrmacbob

Re: Preview app on iMac not saving resized JPG images

Here's Apple Support's article for MacOS 26: Crop, resize, or rotate an image in Preview on Mac - Apple Support

Eg: says:

"Reduce an image’s file size

Go to the Preview app on your Mac.
Open the image you want to change.
Choose Tools > Adjust Size, then select “Resample image.”
Enter a smaller value in the Resolution field.
The new size is shown at the bottom.

Tip: To reduce the file size of multiple images at the same time, display the images in the same window, select them in that window’s sidebar, then choose Tools > Adjust Size."

_____________

Useful resource: Preview User Guide for macOS Tahoe : Preview User Guide for Mac - Apple Support

Reply

Preview app on iMac not saving resized JPG images

Similar questions