
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.
How to merge 2 pdf files
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.
- Open the first pdf file.
(Make sure it opens in Preview) - In the View menu select ‘Thumbnails’

- Either:
- Drag the a new pdf file from the desktop into this thumbnails window OR
- Open the new pdf file then drag a page thumbnail across into this thumbnails window.
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.
An Alternate Method of merging pdf files.
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.

If ‘Save’ doesn’t work, select ‘Print’ then ‘Save as PDF’.
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.
Editing a PDF.
You can also edit a PDF document in preview. Read on for how to Edit a pdf file.
CONTINUE READING >
Hi.
In attempting this I find that Preview continues to treat the 2 documents as 2 documents just combined in the one column. Not sure my question makes sense. :)
I’d like them to be treated as 1 document.
I think I just solved this. You have to drag the second thumbnail directly onto the first thumbnail & not just below it.
Paul do you have Sierra? Because the way you describe (dragging on top) is the way it has worked in every OSX so far, but in Sierra, for me anyway, I don’t need to drag on top to merge, I can drag below or anywhere. That’s not how it works for you?
I have Preview 9.0
I’m trying to edit a pdf document. i.e., change some words.
I’ve opened the toolbox but none of the new menu items seem to have anything to do with actually editing words and sentences.
That’s right, you can’t edit existing words. You can only add new ones. It’s very limited.
After dragging one pdf to the open previewed pdf, it still treats the pdfs as 2 separate documents once i close preview
Read these instructions more carefully. If that fails try printing the document then select ‘save to pdf’.
You are incorrect Wayne. I’ve read this (and many other) articles multiple times and still cannot get it to work properly.
I just tried it and it works.
Are you sure you are using Mac OS Sierra (10.12)?
Do you get a little green plus sign when you drag one page into the other document?
What is not working?
The only way I got this to work on OS Sierra was to click Print and then in the bottom left corner selected “Save as PDF”
Thank you, thank you, thank you!!
Thank you for this sharing, really helpful. I used to merge multiple PDF files with Acethinker PDF Converter, it works pretty well. You just need to launch the app and Go to “Other Tools†tab to choose the “Merge†button. Then, click the files that you want to combine together or simply drop them into the selection box. Click “Convert” will start the combine process, once it’s done, you can save it to your computer. Share it here as an alternative solution.
Thank you–the first method did not work, but the alternate method of “printing” did.
Really nice post: very powerful tools in Previewer. If you had to merge lots and lots of files (e.g. 10+) you can always try Automator which comes with the OS. This allows you to set up a workflow to first ask Finder for items (i.e. your PDFs), then merge them (Combine PDF Pages) before finally moving them (Move Finder Items) to the desktop or some other place where you can find them. Over kill for most applications but sometimes useful to know.
Maybe the author can amend the article. As one of the posters said, you have to drag the second (and/or subsequent files) ON TOP of the existing file in the thumbnail window, not just underneath. If it’s underneath, it’s treated as a separate document.
Otherwise the Print/Save as PDF works fine as well.
The behaviour changes with pretty much every OS that Apple releases. Some you drag on top of and some you drag underneath. So you need to pick the exact article for the OSX version that you have! This article is for Sierra.