How can I combine two PDFs in Preview?
First, you can only merge pdf if they are not protected, if this is the okay :
- Open both pdf
- Enable the sidebar in each windows of Preview, then select "Thumbnails" view
- Drag & drop the cover (inside the sidebar) of one pdf into the sidebar of the other pdf.
With this method, you can completely merge two pdf or selectively drag & drop the pages you want to merge to create a completely custom new pdf.
You can also extract pages from one pdf still using the same manipulation, but drag & drop to the Desktop.
Here's a detailed explanation of how to use Automator. It looks complicated but it only took me a couple of minutes to reproduce it on my computer...
I do this all the time (I print my expense report to PDF and then have to insert all the scanned receipts and other PDF receipts into that document). The easiest way I have found is to open the target PDF in "Contact Sheet" view and then from Finder you can drag and drop the files into the Preview window of the target file. This makes very quick work of assembling multiple PDFs into a single document
A really usefull tool to combine multiple PDFs is the following service:
It allows you to merge several PDF pages online and download the merged PDF file afterwards.