Creating a single PDF from multiple images on MacOS

Creating a PDF with MacOS is a quick and easy process and utilizes the very powerful and often underrated Preview application which comes built in to MacOS, of which I’m a pretty big fan of.

I recently had to explain an issue with a pretty involved UX flow that had about 10 transitions in state. While a video and voice over could have been used, I needed to actually add a few pointers and other graphics to convey the message correctly. Instead of sending 10 individual files which would be difficult for other stakeholders to work with, having a single PDF document with images in order made a lot of sense.

After getting all the screen grabs and edits done, it is a simple case of selecting all of the files, then using Open With > Preview. Instead of opening each of file individually, Preview will actually combine them all into a single context. This is the default behavior, and if it doesn’t work, the setting can be found in Preview > Preferences > Images > Open groups of images in the same window.

After opening the new Preview instance, you are actually able to add new images by dragging files into the left pane, remove images you don’t want to include by using the Close functionality, and re-arrange the order of the files to suit your needs.

After everything is in order, the next step is to use Print. The initial, obvious action might be to actually use Export, but doing so only takes the currently viewed image as the image to export.

The reason for Preview doing this is because it still sees each image as an individual document. To combine them into one document, the print functionality needs to be used.

After clicking File > Print the dialog to print all images appears and from here, you can select the PDF context in the bottom left of the print dialog. You can save directly as a PDF here using the Save to PDF option, but it is better to select Open in Preview. This will open a new Preview window with the difference being that all images in the new window are in the one document, instead of multiple documents as per the initial window that was opened. The reason for opening a new window is that the saving options for the file can be accessed. By selecting File > Export... there is now access to a Quartz Filter option, and selecting Reduce File Size here I’ve found to be a good choice depending on the type of images you are using. Without this option, the PDFs that are created tend to be quite large and depending on your use case, might not need to be super high quality.

In my case, adding a PDF to the relevant ticket for the UX bug was a lot easier to work with than uploading 10 different files. It really helped improve the message that I was trying to convey as there was much less friction for users trying to follow the flow I was communicating.