How to Merge PDFs on Mac for Free — 3 Methods

Mac users have a genuine advantage when it comes to merging PDFs — the built-in Preview app has a surprisingly capable merge feature that many people do not know about. Here are all the free methods to combine PDF files on Mac in 2026.

Method 1 — Preview App (Built into macOS, No Download Needed)

This is the fastest method if you are already on a Mac — no internet connection needed, completely free, built into every Mac.

1. Open the first PDF in Preview (double-click any PDF — it opens in Preview by default)
2. Show the sidebar: View → Thumbnails
3. Open your second PDF in a separate Preview window
4. In the second window's thumbnail sidebar, select the pages you want to add
5. Drag those page thumbnails into the first window's sidebar at the position you want them
6. Save the first document: File → Export as PDF (or Cmd+S)

Limitation: Dragging pages between windows can be fiddly with many files, and there is no "combine entire files at once" button — you work page by page or select-all per document.

Why Preview's Drag-and-Drop Approach Gets Tricky With Many Files

Preview's merge feature works at the page level rather than the file level, which is genuinely useful for selective combining — pulling just a few pages from one document into another — but becomes cumbersome as a general-purpose merge tool. Each additional source file means another Preview window to manage, another set of thumbnails to select from, and more drag operations to perform precisely. For two files, this is manageable; for five or ten files, the process of opening each one, selecting all its pages, and dragging them into the right position in the target document becomes time-consuming and error-prone — it's easy to accidentally drop pages in the wrong position, or miss selecting some pages from a source document. This is the main reason Method 2 becomes more attractive as the number of files grows.

Method 2 — Browser-Based Tool (Easiest for Multiple Files)

For combining many files quickly without the drag-and-drop fiddliness:

1. Open flipfiles.io/pdf-merger.html in Safari or Chrome
2. Drag all your PDF files into the upload area at once
3. Reorder using the up/down arrows
4. Click Merge PDFs
5. Download the combined file

Advantage: Handles any number of files at once, simple reordering, and processes entirely on your Mac — nothing uploaded anywhere.

Method 3 — Automator (Advanced, One-Time Setup)

For users who frequently merge PDFs, macOS Automator can create a permanent "Combine PDF Pages" right-click action:

1. Open Automator (find via Spotlight search)
2. Create a new Quick Action
3. Set "Workflow receives" to PDF files in Finder
4. Add the "Combine PDF Pages" action
5. Add a "Move Finder Items" action to save the result where you want
6. Save with a name like "Merge PDFs"

Afterwards, select multiple PDFs in Finder, right-click → Quick Actions → Merge PDFs.

A Note on the Automator Action's Merge Order

One quirk worth knowing about the Automator "Combine PDF Pages" action: it merges files in the order they're selected in Finder, which isn't always the order you expect, especially if Finder is sorted by a criterion other than name (like date modified). Before relying on the Automator action for a merge where order matters, it's worth either sorting Finder by name first (so selection order matches alphabetical order, which is often the intended order for sequentially-named files) or doing a quick check of the merged result afterward and using the Reorder PDF Pages tool if the order needs adjusting.

Which Method Should You Use?

• One-off merge of 2 files: Preview app (Method 1)
• Merging many files quickly: Browser tool (Method 2)
• Frequent merging tasks: Set up the Automator action once (Method 3)

Reordering Pages After Merging

If pages end up in the wrong order after merging, use our Reorder PDF Pages tool to rearrange them without starting over.

File Size After Merging

Merging does not compress files — your merged PDF will be roughly the sum of the original file sizes. If the result is too large, run it through our PDF Compressor afterwards.

Choosing Between Built-In and Browser Tools More Generally

The choice between macOS's built-in PDF tools and browser-based alternatives often comes down to how often you do a particular task and how much control you need. Built-in tools like Preview are deeply integrated into the Mac experience — no separate website to navigate to, works offline, and feels native. Browser-based tools tend to offer more consistent handling of larger numbers of files and additional options (like the reordering and compression mentioned above) in one place. For a one-off task, whichever is faster to access in the moment is usually the right choice; for recurring tasks, it's worth trying both approaches once to see which fits more naturally into your workflow before settling on one as your default.