To combine PDFs on the Mac, start with two or more source files.
Double-click on the first file to open it in the Preview app, which is the default app for viewing PDF files in mac OS.
Some apps make this task overly complicated, but Preview makes combining the highly portable and multi-platform pdf files incredibly simple, offering drag & drop ease.
Perhaps best of all, you certainly don’t need to pay big extra bucks for a fancy PDF editor application when the Mac has the tools directly within OS X.
You can see that our PDF file has 5 pages now; it was originally a 1-page PDF file, but it has more now that we added another to it: If you don’t need to tack on an entire PDF file to another, you can even opt to selectively add only certain pages from a PDF file to another.
To do this, follow these simple steps instead:1) Have two or more PDF files at the ready, and open them in Preview separately.2) Adjust both Preview windows on your screen so you can see the sidebar in both windows.3) Select a page from the secondary PDF file’s sidebar, and drag the thumbnail over into the sidebar of the original PDF file.4) When you see the green icon on your cursor, you can let go of your mouse and only the selected page will be transferred to the original PDF file. You’ve just successfully transferred a single page from one PDF file to another PDF file.
This is by far the best way to merge PDF files on the Mac.
Not only can Preview combine a variety of single or multi-page PDF docs into a single file, you can even add images as pages, remove a page from an existing file if it’s unnecessary to have in the joined doc, or rearrange the pages of the joined files to be reordered according to your needs.
The end result will be a single merged PDF document that contains every page and input file that you need.
One thing to note about older versions of Preview app is the “Export to PDF” option is not always available, thus these older versions of Preview can still successfully export the combined files as one either by choosing the “Save As” option, or by using the traditional Print to PDF option that is available through the Print menu in all versions of OS X.
Quick side note: joined PDF’s can often be quite large, if the resulting file is too large you can reduce the file size by adjusting the Quartz filter used.