We were surprised to learn that a lot of Mac users weren’t aware of this handy feature that makes your life easier if you resize a large number of images individually.
There are plenty of software out there that’ll do this, but if you own a Mac you don’t need to install any of those. Preview is more than enough.
1. Open all your images in Preview
2. Select all images by pressing Command ⌘+A
3. Go to Tools > Adjust Size
4. Fill in your required dimensions and press OK
Note: To resize all your images proportionately if they aren’t the same size, leave the height field at ‘Multiple values’ and tick the ‘Scale proportionally’ check box.
Thats it. Hope this comes in handy .