Combining PDFs is one of those jobs people pay for online without realising their Mac already does it. Whether you’re putting together a job application, a set of invoices, a signed contract and its appendices, or scanned pages, you can merge them for free, without uploading anything. This guide covers five ways, when to use each, and the one mistake in Preview that catches almost everyone.
Which method should you use?
| Method | Best for | Choose page order | Only some pages | Keeps originals |
|---|---|---|---|---|
| Finder Quick Action | Whole files, fastest | By selection order | No | Yes |
| Preview | Picking and arranging pages | Drag thumbnails | Yes | Only if you duplicate first |
| Shortcuts | Repeating the same merge often | Input order | Yes, a page range | Yes |
| Terminal | Scripts and many files | Argument order | No | Yes |
| A PDF app | Large batches, folders, reordering visually | Drag cards | Varies | Yes |
Method 1: Finder Quick Action (the fastest way)
- Open the folder with your PDFs in Finder.
- Select the files in the order you want them in the final PDF: click the first, then Command-click each of the others in turn.
- Control-click (or right-click) one of the selected files and choose Quick Actions › Create PDF.
The combined PDF is saved in the same folder, named after the first file you selected. Your original files aren’t changed.
You can also use the Create PDF button in Finder’s preview pane (View › Show Preview) with several files selected. And it isn’t limited to PDFs: you can mix in JPEG, PNG and HEIC images, and each becomes a page.
The catch is that there’s no screen to check or reorder pages. If the order comes out wrong, delete the new PDF and select the files again in the right order. Renaming files with numbers first (01 Cover, 02 Contract…) and selecting them top to bottom makes this easy.
Method 2: Preview (pick, reorder and mix pages)
Preview gives you the most control of the free options, because you can see every page.
- Make a copy first. Open the first PDF in Preview and choose File › Duplicate (Shift-Command-S). Work in the duplicate. (See the warning below for why.)
- Choose View › Thumbnails (Option-Command-2) to show the page sidebar.
- Drag the second PDF’s file icon from Finder onto the sidebar, dropping it where you want its pages to go: between two thumbnails, or after the last one.
- Drag thumbnails up or down to reorder pages. Select a page and press Delete to remove it.
- Choose File › Save, or File › Export as PDF to save under a new name.
You can also insert a whole file from the menu: click a thumbnail, then choose Edit › Insert › Page from File, pick the PDF, and all of its pages are added after the selected page. If the menu item is greyed out, click inside the document window first.
Merging only some pages
To take just a few pages from one PDF into another:
- Open both PDFs in Preview with View › Thumbnails showing.
- In the source PDF, Command-click the thumbnails you want (or Shift-click a range).
- Drag them into the other PDF’s sidebar.
To make a brand-new PDF from selected pages, drag the selected thumbnails to the desktop, or copy them and choose File › New from Clipboard.
Why your Preview merge didn’t work
- You opened several PDFs, but they’re still separate. Opening multiple PDFs at once puts them in one window as separate documents. They’re only merged when you drag pages onto the thumbnails of one document.
- The saved file has only one page. You probably exported while one page was selected, or saved the wrong document in the window. Check the page count in the sidebar before saving.
- It won’t save at all. The PDF may be password-protected or locked. Remove the password first (you need to know it), or save a copy with Export as PDF.
Method 3: Shortcuts (for a merge you repeat)
If you combine PDFs regularly, a shortcut turns it into one click.
- Open the Shortcuts app and create a new shortcut.
- Add the Make PDF action. When it receives several files, it merges them.
- Click the action’s options: Merge Behavior can be Append (one file after another) or Shuffle (alternating pages, handy for double-sided scans), and Include can be All Pages or a Page Range.
- Add a Save File action to choose where it goes.
- In the shortcut’s details (the info button), turn on the option to use it as a Quick Action in Finder, so it appears when you Control-click a selection of PDFs.
The Shuffle option is the hidden gem here: if you scanned all the front sides of a document and then all the back sides, it interleaves them back into the right order.
Method 4: Terminal (for scripts and many files)
macOS still includes the PDF-combining tool used by Automator. Older guides point to a Python script called join.py, which no longer exists on current macOS; it’s now a compiled tool in the same place. To merge files in a set order:
"/System/Library/Automator/Combine PDF Pages.action/Contents/MacOS/join" -o ~/Desktop/merged.pdf first.pdf second.pdf third.pdfThe files are combined in the order you list them. Add --shuffle to interleave pages. To merge every PDF in a folder in name order, cd into the folder and replace the file names with *.pdf. It prints nothing when it succeeds; check your desktop for merged.pdf.
Automator’s Combine PDF Pages action uses the same tool, if you prefer to build a workflow there.
Method 5: a dedicated PDF app
The built-in tools cover the basics, but they get awkward with lots of files: Finder gives no preview, Preview’s autosave is risky, and Shortcuts needs setting up.
MightyBench’s Merge PDFs shows each file as a card you drag into order (or use Move Earlier and Move Later), takes a whole folder at once in name order, and saves one new PDF with every page, leaving the originals alone. There’s no size cap and no watermark, and nothing is uploaded. To arrange individual pages from several files in one grid, rotate them or drop some, use Organize PDF instead.
After merging: make the PDF smaller
Merged PDFs, especially of scans or photos, can get too big to email. Preview has File › Export with a Quartz Filter menu that includes Reduce File Size, but it often makes images blurry. A gentler option is Compress PDF, which recompresses only the images and leaves the text exactly as it was. If you’re assembling photos rather than PDFs, Images to PDF makes one page per image, upright and in your order.
Frequently asked questions
Can I combine PDFs on a Mac for free?
Yes. Finder’s Quick Actions › Create PDF, Preview, the Shortcuts app’s Make PDF action, Automator and the Terminal are all built into macOS and free. None of them upload your files.
How do I merge PDFs on a Mac without Preview?
Select the PDFs in Finder in the order you want, Control-click and choose Quick Actions › Create PDF. You can also use the Make PDF action in Shortcuts, or the join tool in Terminal.
How do I choose the page order when combining PDFs?
In Finder, the files are combined in the order you select them, so Command-click them one by one in order. In Preview, drag the page thumbnails into the order you want. In Terminal, list the files in order.
Does Preview change my original PDF when I merge?
Yes. Preview saves changes automatically into the file you opened, even when you close the window. Choose File › Duplicate before you start, or File › Export as PDF to save the merged document as a new file.
Can I merge only certain pages from a PDF?
Yes. In Preview, show the thumbnails, Command-click the pages you want and drag them into the other PDF’s sidebar. In Shortcuts, set the Make PDF action’s Include option to a page range.
Can I combine images and PDFs into one PDF on a Mac?
Yes. Select the images and PDFs together in Finder and choose Quick Actions › Create PDF. Each image becomes a page, in the order you selected the files.
How do I undo a PDF merge in Preview?
Open the file and choose File › Revert To › Browse All Versions, then pick a version from before the merge. Use Edit › Undo if the document is still open.