If you have three separate PDF documents—such as a cover letter, a resume, and a list of references—and you need to submit them to an online application portal as a single, unified file, you do not need to purchase expensive third-party software like Adobe Acrobat. macOS includes a highly capable tool natively built into the operating system called Preview, which allows you to seamlessly combine PDFs in seconds.
Preparing the Files
To make the process as simple as possible, ensure all the PDFs you want to merge are saved in the same location, such as your Desktop or your Downloads folder.
How to Merge the PDFs
- Double-click the very first PDF document you want to act as the “base” file (e.g., your cover letter). By default, macOS will open it in the Preview application.
- At the top of your screen in the main menu bar, click on View.
- From the dropdown menu, select Thumbnails. A new sidebar will appear on the left side of the Preview window, displaying a tiny, numbered preview of the page you are currently viewing.
- Now, open a standard Finder window and locate the second PDF file you want to attach (e.g., your resume).
- Click and drag the icon of the second PDF directly from the Finder window into the left-hand Thumbnails sidebar of the Preview window.
- As you hover your mouse over the sidebar, you will see a green “+” (plus) symbol appear. Drop the file into the sidebar.
The second PDF will instantly unpack itself, and all of its pages will populate the sidebar below the original document. The two files are now merged in memory.
Reordering and Saving
If you accidentally dropped the second document in the wrong order, you can simply click and drag any of the thumbnail images up or down within the sidebar to perfectly reorganize the sequence of pages.
Once you are satisfied with the order:
- Click on File in the top menu bar.
- Select Export as PDF.
- Give your newly combined document a clear name, choose where you want to save it, and click Save.
You now have a brand new, single PDF file containing all the pages from your disparate documents, perfectly ready for submission.