Mar 10


Thanks so much. Your explanation is brilliant. Easy to follow. Better than apple support itself. :)

OS X comes with a free application called ‘Preview’ that will open automatically whenever you click on a pdf file. Preview can edit and merge pdf files but the official Apple instructions are not quite right. Here’s how to do it depending on which version of OS X that you have.

Preview app

You can merge PDF files using the built in ‘Preview’ application that comes for free with OSX, you don’t need 3rd party paid software.

The basic concept for merging 2 pdf files is the same for whatever version of OS X you have. You open the first file, view the page thumbnails, then drag the second file into the first file and save the new file.  Exactly how this works varies depending on which version of OS X that you have. Apple have changed the details a few times. Sometimes there’s a green plus sign to indicate the merge. Sometimes there’s a grey border. If you don’t get it right the 2 files will not merge.  You need to read the directions for the exact OS version that you have. (To find out which version of OSX you have just go to the Apple Menu and click ‘about this mac.’)

Please click on the version of OSX that you have to find out how to merge a pdf file:

How to merge PDF files in High Sierra (10.13)  (2018)

How to merge PDF files in El Capitan (10.11) (2015)

How to merge PDF files in Yosemite (10.10) (2014)

How to merge PDF files in Mavericks 10.9 (2013)

How to merge PDF files in Mountain Lion 10.8 (2012)

For all versions of OS X prior to Mountain Lion (10.7 and earlier)  just follow the instructions below.

Here’s how to  join two or more pdf files together using Preview in OS X 10.7 and earlier:

1 Open the pdf file in preview.

2. Open the thumbnail view (Shift-⌘-D)

3. Drag a second pdf ON TOP OF an existing page  thumbnail.

When you drag in step 3 it must drag to on top of the thumbnail, as in over it, not above it.

This is a bit hard to explain, the best way to grasp the concept is to look at the pictures below. Can you notice that the thumbnail on the right has an extra grey border compared to the thumbnail on the left. The grey border indicates that the files are merging.

WRONG WAY: If you drag the new pdf file underneath the existing pdf they are not merged.

RIGHT WAY: Drag the new pdf file overlapping an the existing page and they will merge into one – creating one pdf document out of the two. (Notice the extra grey border compared to the left photo.)




SUMMARY: To combine two separate PDF files into one document you need to drag the new pdf ON TOP OF an existing  thumbnail until the grey border appears – then it will merge the two pdfs together.  (You can then save the new merged pdf.) 

If you drag it into the sidebar but not on top of an existing page the new file will be added as an external link – not merged into the original pdf document.

Published Date:Last Updated: Dec 2017.

Read on for how to do it step by step.


584 Responses to “How to merge two pdf files in OSX”

  1. Jon says:

    This works on Snow Leopard too. Instead of dragging new pages below the first page, drag them onto the icon of the first page in the sidebar. Annoying change i’ll admite

  2. Pirko says:

    If you have a problem saving all individual pdf files into one file, do this: 1/ select all files you want to merge; 2/ open all in one go with Preview; 3/ re-arrange if necessary in the sidebar and make sure all files are selected (highlighted); 4/ print, but make sure to print to a pdf file !!!! (this is an option in the print pop-up menu). Done.

  3. Andrew says:

    I’m running 10.5.8 and I couldn’t get this working at all. Absolutely nothing happened when I dragged the second file into Preview.

    Any ideas, please?

  4. Pirko says:

    To Andrew: I’m running 10.5.8 as well. Select all pdf files and open with Preview. If the files are opened each in their own Preview window, then make sure sidebar is active in all of them (see View menu item), and you can simply drag the different pdf files into the sidebar of one and the same Preview window. Now you have all files in one Preview window, you can close all the rest except this one, and you can re-arrange in the sidebar by dragging and finally print to a pdf file.

    P.S. 1. Whether a group of files are opened in one Preview window or in several is an option you can set in Preview references; but it doesn’t really matter for this exercise as you can drag them into one window as you choose.
    P.S. 2. The print menu is a great tool for creating pdf or other image files from text files or any other formats.

  5. Nate says:

    Make sure you select “thumbnails” and not “table of contents” at the bottom. If you aren’t looking at thumbnails nothing will happen.

  6. Jon K. says:

    Why does Apple do weird things like this? Just when we get used to doing one thing – they go and change it on us. Grrrrrr.

  7. Andrew says:

    10.6 / Snow Leopard has not killed PDF merging. Delighted to just discover that it’s simply a case of dropping the imported page ON TOP of the page to be merged with.

    If you just drop it in the side bar, it assumes that you are just gathering documents to view together.

  8. Bob says:

    Great tip! Tried to find this in the Help on my Mac, but no dice. Had to go to the Wide World of Web.

    Kavi, the file size is probably a result of how the files were created. I scanned seven pages on a Brother MFC, @ 100 x 100 DPI (sufficient to make a legible copy of the doc) and ended up with 432 kb.

  9. Andrew says:

    Okay – no idea why, but it all worked this time. I even found that I can drag a JPG which I’d opened in Preview onto the sidebar of the PDF I’d opened there and save the modified PDF.

    Good stuff, Apple!

  10. dimisec says:

    Wonderful and very useful – did not know that feature before – thanks!

  11. Henrik says:

    Thanks – a great tip – it just helped me a lot. However, I need now a tool to reduce the size of the resulting pdf-file…

  12. Chensong says:

    Very nice post. Works for Snow Leopard for sure.

  13. Jeanette says:

    Thanks Andrew. Now I get it! Yes you have to drop it ON TOP of the existing page like pasting over it, and not insert it on top of the page! I’m using Snow Leopard10.6 and it worked!

  14. Andrew says:

    ah…! great tip … and i finally read the instructions properly … i had the same problem with dragging the various pages and then saving only to find that only one page had saved.

    so in snow leopard, you really do have to drag successive pages on top of the first page.

    cheers and thanks for the tip

  15. Joe says:

    Something very odd is happening for me. I’m using Snow Leopard. I can drag the thumbnail of a one-page PDF and combine it into other PDF’s but it doesn’t work with multi-page PDF’s–I can’t combine them into other PDF’s. I can’t get it to work any way I try. Help!

  16. Helen says:

    Thank you so much, Pirko. After struggling for hours, I finally read your suggestions. Two minutes later, I had my combined PDF file. :)

  17. Umair says:

    Thanks a lot dude.. it just awesome. i have been trying since couple of hours. but eventually u have save my day..

  18. Pete says:

    Thanks for the tip. I had spent some time trying to find how to merge files before going on the net. So easy, when you know how!

  19. Dan says:

    The above tip to drag the documents to the preview in the sidebar is the right answer. It creates a PDF binder icon then and the files stay together when you save. Just dragging it in uses preview to ‘view’ all the documents together.

  20. Gunnar says:

    Thanks a million! I thought this would be a real pain but Mac has it built into the system. The brilliance of Apple again. Thank you so much for sharing!

  21. Happy once again that it switched to mac!

  22. Dawn says:

    I was enjoying this feature and then I had to download adobe reader for business reasons and a nonexistent plugin for my OS, now Sidebar is gone and only Pages exist and I no longer know how to combine documents. Just as I was comfortable now something new does not seem to exist for Adobe reader as in PDF Viewer. Help Please!

    • Anthony says:

      Had the same problem but I found a solution.
      Google for RCDefault and you can download an app that will install in your preferences pane. With the app you can set the preferred application again and eliminate the Adobe overwrite.

  23. Carolyn says:

    Wow….that’s fantastic – converting my thesis to pdf kept separating out pages formatted in landscape from portrait but your instructions made it possible for me to merge it all as one pdf document. THANK YOU!

  24. mark says:

    thanks everyone… i have spent so long on trying to work this out… well until I reached this board.

  25. John Sal says:

    i am so frustrated! this doesnt seem to work with my computer….and i have snow leopard

  26. GAby says:

    Awesome tip, I’m everyday more into Mac… (Just converted)

  27. Rod says:

    Thanks for the tip and the clear explanation. I read about this on another site, but the reference was vague.

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