How to Open All Images Into One Window in Preview for Mac

If you open multiple images into Preview on a Mac with some regularity, you may notice that sometimes pictures are grouped into single windows, and sometimes images are opened independently each into separate unique windows. If you’d rather all images be opened into a single window of Preview app on the Mac (or into unique windows for that matter), you can make a settings adjustment to achieve this.

This is a simple usability adjustment that can make the Preview image viewer on the Mac a bit less cluttered.

Open All Images Into a Single Preview Window on Mac OS

1. Open the Preview app in Mac OS and go to the “Preview” menu, then choose “Preferences”
2. Under the ‘General’ preferences tab, look for “When opening files” and choose “Open all files in one window”



3. Close Preferences and open a group of images into Preview, all images will now open into a single preview window

Opening all files and images in Preview into a single window will look like this:

Compared to this, where some files will open in separate windows within Preview, but some will be grouped as well, depending on when and how they were opened in the app:

This capability is best used with thumbnails in the sidebar of Preview, so if for some reason you are hiding those be sure to enable the thumbnail viewer as part of the Preview app by clicking the sidebar option in the Preview tool bar.

Of course if you like the default behavior of opening groups of files into the same window, meaning some files will open into into separate windows and some will be grouped, you can return to the Preview preferences and set that with “Open groups of files in the same window”, or you can cause every single file and image to open into a unique separate window with “Open each file in its own window”.

For some quick background, Preview is the default image viewer in Mac OS, which can not only open and view pictures and photos but also make edits, add text captions, convert pictures, resize pictures, rotate, crop images, fill out pdf forms, sign documents, batch convert image formats, import photos from cameras, and so much more, it’s really one of the better under appreciated apps on the Mac.