Combining pdf documents on an Apple computer is easy. Leopard and Snow Leopard (the latest versions of Macintosh OSX that come on your computer) have the ability to move pdf pages within a pdf file around and even merge two different pdf documents together. It’s built right in to OS X for free – you don’t need a third party program to do it!
To join two or more pdf files together using Preview (the standard pdf viewer in OS X) simply open the pdf file in preview, open the thumbnail view (Shift-⌘-D), and then drag a second pdf file ON TOP OF an existing page thumbnail. (It must be on top of the thumbnail, 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 seperate PDF files into one document you need to drag the new pdf ON TOP OF an existing thumbnail and it will merge the two together. 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.

Drag the new pdf file under the existing one and it will insert a thumbnail that links to the second pdf but they are not merged.
.
.
.
The blue line that appears underneath the original pdf lets you know the files are NOT being combined. Move the pdf on top of the other pdf so that the blue line disappears.
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).

In Leopard select 'Sidebar'
3. You can now drag the second pdf file (from a folder or from your desktop) 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. 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.
In some older versions of Preview, if you drag the second file on top of an existing page in the sidebar, it will appear as a red box to show you it will be merged, or as a red line to show you it will not be merged. In the latest version of preview, the red box does not appear, but the same principle applies – drag it on top of the existing thumbnail to merge the two documents.
You can now save it – 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.

No – you can’t reduce the file size of the new PDF document – you can’t get everything for free! To do this you Adobe Acrobat Professional.
Like this article ? Click here to for how to make a pdf booklet. Also here for how to reduce the file size of a pdf.
Share


Excellent description, very helpful. I had my pdfs combined in a couple of minutes.
Thanks
This is such a clumsy procedure. I find it difficult to believe that Apple makes this necessary. Surely when converting a word doc either by the “save as” or “print” functions, a real PDF can be created!
Very frustrated with my Mac at the mo!
I’m really struggling with this. I’ve been able to drag a couple of sheets onto the first one but after a few, the line is either above or below the thumbnail and won’t combine. Anyone know what I’m doing wrong?
Got it fixed! Downloaded BATCH PDF MERGER! Works a treat too!
Steve,
Using Preview to merge PDF files or re-order pages really couldn’t be any easier than dragging them from one window to another. You’re likely accidentally getting it to do the wrong thing. I have had trouble too. I find that opening the pdf files singly (so they don’t open in the same window) and dragging from sidebar to sidebar makes things much easier.
As for getting multiple PDFs when you print from Word, this is a Microsoft issue. Word will create multiple print jobs from a single file if the formatting in the document changes in such a way that it is needed. It’s the only application I can think of that does this.
Thanks for the tip JP. Couldn’t figure it out until i tried dragging from open preview to another.
I wish I was as successful as the last few posters seem to be. I followed the instructions, dragged the 2nd pdf on top of the 1st thumbnail in the sidebar and NOTHING. I even tried closing and re-opening both files and still nothing. I drag & release right on top and nothing happens.
If you wrote an article about life we’d all reach enlighmtneent.
I’m surprised people are having difficulty with this, it’s a pretty straightforward procedure.
The only thing I can think might be going wrong is you’re opening the second PDF file when all you have to do it drag ‘n drop the file itself on top of the thumbnail. I’ve done this several times and never had any issue.
thank you very much! it is really helpful when have to edit scanned images of the book and then save them as one document!!!
Is anyone running 10.7.2? Dragging a PDF file onto a PDF thumbnail in preview only lets me insert the PDF in front of or behind the opened PDF. It is impossible to drag and release the file overtop the preview PDF (as explained in this article for Leopard).
I have 10.7.2 and it works as described. Maybe the pdf you are trying to merge into locked?
Paul–
I was having trouble on 10.7.2 with the same problems you described, but solved it by clicking “Thumbnails” from the “View” menu, instead of “Sidebar.” Then just drag the new file wherever you want the new pages to go. Works like a charm!
To the admin/blogger: thanks for posting this how-to!
This is not working for me at all. I have OSX and my Preview is version 5.0.3. I have followed exactly what is written above and nothing happens when I release my mouse as I am hovering over the first page. Nothing pops up in the sidebar, no error message appears, it doesn’t do anything.
Maybe the pdf files are locked? When you make a pdf file you can ‘lock’ it so no-one else can modify it. Did you make the pdf files?
Does anyone know how to preserve the page number as it was in Word? I managed to combine the pdf files (the multi pdf files created from a single word document) but I need to preserve the page number. Can anyone help.
Very clear, thank you!
thanks a lot. description is very helpfull. ı achieve it at the end :)
Ok, I think I know the problem.
If you are trying to merge two .pdf documents with multiple pages you cannot just drag one on to the other using the thumbnail. Instead, you have to expand the preview in the side-bar (click on the thumb nail once) and then drag the pdf into the newly expanded area.
I hope this helps.
That’s helpful thanks Chris.
iMac 21″ Lion 10.7.2
It does not work in Lion to merge 2 pages on one…
Any help?
Worked perfectly for me, thank you!!