How to Merge PDFs on Mac (3 Free Methods)

Macs merge PDFs out of the box, and most Mac users do not know it. There is no need to install anything, upload anything, or sign up for anything — the tools are already on the machine, and they handle everything from combining two files to processing a folder of two hundred.

Method 1: Preview — the one to use

Preview merges PDFs by drag and drop:

1. Open the first PDF in Preview.
2. Choose View → Thumbnails to show the page panel down the left side.
3. Drag another PDF from Finder into that thumbnail panel, dropping it where you want its pages inserted. A blue insertion line shows where it will land.
4. Repeat for each additional file.
5. Drag thumbnails to reorder anything that is out of sequence.
6. Choose File → Export as PDF and save under a new name.

Use Export as PDF, not Save. This is the step that catches people. Plain Save writes the combined result back over the first file, destroying your original. Export produces a new document and leaves the source intact.

A few refinements worth knowing:

• Drop onto the panel, not the page. Dragging a PDF onto the main page area inserts it as an image on that page rather than adding its pages. If you end up with a picture of a document instead of a document, this is what happened.
• Select before dropping if you want pages at the very end — click the last thumbnail first, then drop below it.
• Cmd-click to multi-select thumbnails for deleting or rotating several at once.
• Delete unwanted pages by selecting them and pressing Delete before exporting.
• Rotate misoriented pages with Cmd-R while they are selected. See how to rotate a PDF page.

Preview is ideal for anything up to roughly a dozen files. Past that, the dragging gets tedious.

Method 2: Automator or Quick Actions — for batches

For merging many files, or for a merge you perform regularly, Automator turns the job into one click.

1. Open Automator from Applications.
2. Create a new Quick Action (or a Workflow, if you would rather run it manually).
3. Set it to receive PDF files in Finder.
4. Add the Combine PDF Pages action, set to append pages.
5. Add a Move Finder Items action to put the result somewhere sensible, such as the Desktop.
6. Save it with a name like "Merge PDFs".

Because it is a Quick Action, you can now select any group of PDFs in Finder, right-click, and merge them from the Quick Actions menu. Nothing is uploaded and there are no limits.

One quirk: Combine PDF Pages processes files in the order Finder hands them over, which is generally the order shown. Naming files 01-, 02-, 03- makes the sequence deterministic instead of hopeful.

Method 3: The command line — the most precise

If you are comfortable in Terminal, macOS ships with a Python script that does this directly:

"/System/Library/Automator/Combine PDF Pages.action/Contents/Resources/join.py" -o merged.pdf file1.pdf file2.pdf

Or install qpdf via Homebrew (brew install qpdf) for finer control:

qpdf --empty --pages *.pdf -- merged.pdf

qpdf also merges page ranges rather than whole files — qpdf --empty --pages a.pdf 1-3 b.pdf 5 -- out.pdf — which is the fastest route when you want selected pages from several documents.

What about online mergers?

Web tools like iLovePDF and Smallpdf merge PDFs too, and they work fine. But on a Mac they are strictly worse than Preview for this task: they require an upload, they impose daily limits, and they need a connection. The only real reason to use one is if you are on a machine that is not yours.

For anything containing personal, financial, medical, or client information, use Preview or Automator. Those documents never leave your Mac.

A note on our own scope, to be clear rather than promotional: Docento.app is a browser-based editor for signing, annotating, and filling PDFs, and a compressor. It does not merge documents. Once your files are combined by one of the methods above, it is a good place to sign or annotate the result — but for the merge itself, Preview is genuinely the better tool and you already have it.

After merging

Combined documents are almost always bigger than expected, especially when scans are involved, and mail servers commonly reject attachments over 10–25 MB. Compressing the merged file usually solves this with no visible quality loss.

Then check the result: page order, orientation, and that no file was silently skipped. And if you need the reverse operation later, extracting pages from a PDF covers splitting it back apart.

On Windows or Linux?

Windows has no built-in merge, but PDF24 Creator and PDFsam Basic are free and work offline. On Linux, pdfunite from Poppler is a one-liner. See how to combine PDF files for the cross-platform version of this guide, and best free Adobe Acrobat alternatives for a broader comparison.