How to Merge PDF Files on a Mac with Preview (for Free)

Time needed: 2 minutes

To combine two or more PDF files into.a.single document using macOS Preview on a Mac:

1. Open the PDF files you want to combine in Preview.

   Here’s how: Highlight the files in Finder, for example, click on the selection with the right mouse button and select Open With | Preview from the context menu.
   

2. Make sure thumbnails are visible in the Preview sidebars.

   Here’s how: Select View | Thumbnails from the menu.
   Preview keyboard shortcut: You can also press Command Option 2.
   Every window: Make thumbnails visible for all windows.

3. Duplicate the document whose pages you want to see at the end of the combined PDF file.

   Here’s how: Select File | Duplicate from the menu.
   Keyboard shortcut: Press Command Shift S to duplicate.
   Save as…: Think of duplicating as saving a copy with a new name; this is so the original PDF remains intact.

4. In the PDF whose pages you want to come before that in the resulting PDF, select all pages in the thumbnails sidebar.

   Here’s how: Click in the sidebar and press Command A.
   Not all: You need not select all pages; you can also combine only select or individual pages if you only select those in the sidebar.

5. Drag and drop the preview images to the sidebar of the duplicate

   Side by side: You can position the windows overlapping or side by side to do this, or switch windows using Mission Control, for example.
   Plus sign: The mouse cursor will gain a plus sign to indicate copying.
   On top: It is easier to build the combined PDF from the back, but you can insert the copied pages anywhere, of course.
   

6. Repeat the copying for all files you want to combine.

7. Save the combined PDF.

   Their word: Apple include information on merging PDFs in the Preview User Guide.