Combining pdf documents in OSX is now easy. Leopard and Snow Leopard have the ability to move pdf pages around and even merge two pdf documents together. It’s built right in to OS X –  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 a pdf in preview and then drag a second pdf file ON TOP OF an existing thumbnail, and the two documents will merge. Read on for step by step instructions.

SUMMARY: 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.

Drag the new pdf file under the existing one and it will open but not merge.

Drag the new pdf file on top of the existing one and it will merge.

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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). This will make a sidebar appear on the right side of the window with thumbnails of the pages in it..

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) 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.

Drag the new pdf file under the existing one and it will open but not merge.

Drag the new pdf file on top of the existing one and it will merge.

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 of the merged fles, or you can use use ‘save’ to save over the existing document adding the new pages to it.

Like this article ? Click here to for how to make a pdf booklet.