Apple’s built in pdf reader app called ‘Preview’ can merge 2 PDF files and edit PDF files. In macOS Sierra 10.12 all you need to do is drag the thumbnails that you want to merge from one PDF document to the other and then save the document.
Read on for some screenshots of what this looks like.
Apple have made a change in Preview in macOS Sierra so that when you drag a thumbnail from one PDF document to another, that page is automatically merged into the new PDF document, no matter where you drop it. This makes it really easy to merge two PDF files.
Here is a picture of the thumbnails window open, and I am dragging a PDF document into the thumbnails window:
4. Select “Save” from the File menu to save the new merged document.
Some people are reporting that this method doesn’t work. For some people even Apple’s own instructions do not work. If ‘saving’ the pdf file doesn’t work for you, then after you merge the files, instead of choosing ‘Save’ go to File menu and select ‘Print.’ Then don’t print, but select ‘Save as PDF.’ This will save the merged documents as a new pdf file.
I have tested both methods (Save and Print) on my Mac and they both work. You may have to try both and see which works for you.
You can also edit a PDF document in preview. Read on for how to Edit a pdf file.