Feb 10


Combining pdf documents on an Apple computer is easy. The OSX built in preview application has the ability to merge two different pdf documents together and even move pdf pages within a pdf file.  For all versions of OS X prior to Mountain Lion (that is Leopard,  Snow Leopard, Lion)  just follow the instructions below. Things have changed a little with Mountain Lion so I’ve made a new post on merging two pdfs in Mountain Lion, and there’s another slight change with OSX 10.9 Mavericks.

There are lots of websites offering to sell software to merge PDF files, but you don’t need a third party program to do it – it’s built right in to OS X for free.

OS X has a bilt in free application called ‘Preview’ that opens automatically whenever you click on a pdf file. It turns out that Preview can also edit and merge pdf files.

To join two or more pdf files together using Preview simply open the pdf file in preview, open the thumbnail view (Shift-⌘-D), and then drag a second pdf ON TOP OF an existing page  thumbnail. (It must be on top of the thumbnail, as in over it, not above it, see the pictures below). The two documents will merge into one.  Then save the new combined file. Read on for step-by-step instructions.

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 double 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. See these two pictures below to visualise the difference.

WRONG WAY: If you drag the new pdf file under the existing one they are not merged – it will only insert a thumbnail link to the second pdf. (Single grey border)

RIGHT WAY: Drag the new pdf file on top of the existing one and they will merge into one – creating one pdf document out of the two. (Notice the extra double grey border.)





Here’s how to do it step by step.

1. Firstly, open one of the pdf files in Preview. Preview is the default application that a pdf will open into so if you just double click on the pdf file it will open in Preview.


2. Now go to the menu at the top of the screen called ‘View’ and click on ‘Sidebar’ (or  ‘Show Sidebar’ if you have Snow Leopard). Alternatively, press Shift-Command-D to show the thumbnails. This will make a sidebar appear on the right side of the window with thumbnails of all the pdf pages in it. (See these pictures below).

NOTE: In Mavericks (OSX 10.9) you need to go to View:Thumbnails not View:Sidebar. For full Mavericks instructions see here.


In Leopard select ‘Sidebar’

In Snow Leopard and newer versions of Preview select ‘Sidebar’ then ‘Show Sidebar’

3. You can now drag the second pdf file (from a folder or from your desktop) or even a page from within the second pdf file (from thumbnail view)  into this sidebar window, and it will be added to your pdf document as an additional page.


Drag the new pdf from the desktop onto an existing thumbnail.

To merge the two files you need to drag the new pdf ON TOP OF an existing  thumbnail. (You will get a double grey border. See the picture below.

Drag the new pdf file on top of the existing one and it will merge. Notice the grey double border to show you the files will merge.

In older versions of Preview like Leopard, you get a red line to show you it will not be merged.

With Snow Leopard you get a blue bar to show they will not be merged.

In Lion no lines appear at all if they are not going to be merged.

But in all cases you get the second grey border  to show they will merge.


You can now save the new merged file – use ‘save as’ to save a new document with the merged fles, or you can use use ‘save’ to save over the existing document, adding the new pages to it.




An alternate way if you have lots of pdfs to merge.

Here’s an alternate way suggested in the comments below. It’s much faster if you have multiple files to merge.

From “Finder”, select and click all the pdf’s you want to assemble.
This will open them all at once in “Preview”.

Pick the “File” dropdown menu .
Pick the “Print” dropdown menu.

In the lower left hand corner, click the arrow next to “PDF”.

Click “Save to PDF”.

This will save all the separate pdf files into one pdf document.



Here are some more Macintoshhowto articles to do with pdf documents:

Click here for how to reduce the file size of a pdf file.

Click here for how to edit a pdf document.

Click here to for how to make a pdf booklet.

538 Responses to “How to merge two pdf files in OSX 10.6 – 10.8”

  1. Janos says:

    Very good explanation, It helped! thanks

  2. Katrina Currier says:

    Thanks for these helpful tips! Can you explain how to undo these actions? I have merged too many pages and now want to delete a few of the pages I dragged in, without deleting the whole merged file. Is this possible? Thanks!

  3. Mary says:

    Great!! Thanks a lot, the process is way to fast and easy :)

  4. Rubi86 says:

    Thank you! it worked :)

  5. Ian says:

    This is great and worked perfectly. I became an Apple convert some years ago, in a computing context it was the best thing I did.

  6. Ade says:

    thank you so much. this really helpful !! :)

  7. jeanh says:


  8. EFalk says:

    Such a small detail, but figuring out the right way such that you can actually save the combined document was SO helpful!

  9. Lisa says:

    At midnight and after hours of frustration, this was a God-send! Thank you so much.

  10. SK says:

    Thank you SO much! I kept putting the thumbnails after the original (like on a PC) and it obviously didn’t work. I’m so thrilled and grateful!

  11. Otto the Automator says:

    The ability to combine (merge) multiple PDF files into one file in the Finder is built-into OS X, you just have to turn it on:



    • Wayne says:

      Looks great. Although that’s a very complicated way to do a very simple task that can be done much more simply in Preview. But, it might be good if you have a lot of pdf files to merge or you do this task on a regular basis. Thanks for the link.

  12. Richard says:

    This is not working for me, no double border appears, files don’t merge, remain as 2 documents

  13. TYBAN says:

    This article is worthless, doesnt work

  14. Keith says:

    I usually consider myself savvy when i read these tips, but I’ve spent 90 minutes trying to make Lion do what this article says it will do with absolutely no luck.

    The sidebar method doesn’t work either. When I click on “view” and scroll down to “sidebar”, I’m offered two dead grey choices, neither of which are clickable (“collapse all” or “expand all”). No sidebar appears anywhere.


  15. Mariana says:

    Thank u very much, saved my life, I was going crazyyyyy

  16. Ken says:

    Thanks for taking the time to put these steps on the web! I’m not sure why some are having problems. It worked perfectly for me. I really appreciate the detailed instructions.

  17. Park says:

    Thanks! . . . Works easily.

  18. Danny Coyle says:

    I used this and it worked except it changed the landscape pages to portrait and messed them up, help?

  19. Hannah says:

    I can easily follow the steps and drag one file ON TOP of the other and I see the double boarder. But once I release the second file on top of the first, nothing happens…? I’m lost what to do next! I tried to Save As and reopen, but its only the 1st file. Any suggestions?

  20. Lanelane says:

    Worked for me. Thanks

  21. Dunks says:

    So simple, so obvious.
    So simple and obvious that it needed to be pointed out!

  22. Jakob says:

    This was soooo helpful. Can’t thank you enough. After spending hours trying to find another program, sometime it’s the simplest solutions. Many thanks!

  23. John Satan says:

    Excellent tip! Took some doing, though…in my version of 10.6.8 I had to ‘select all’ pages in the sidebar and then click ‘Print Selected Pages’ in order for all to be merged into one file. Thank you.

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