How to Merge PDF Files on Mac: 3 Free Methods in 2026
Mac users are lucky to have several built-in options for merging PDFs — but they're not always obvious. If you've been paying for Adobe Acrobat just to combine PDFs, you're spending money unnecessarily. Here are three completely free methods to merge PDFs on a Mac in 2026.
Method 1: Browser-Based PDF Merger (Easiest, Most Reliable)
The simplest method is to use ToolFlow's PDF Merger directly in Safari or Chrome on your Mac.
Steps:
- 1Open Safari and go to toolflow.tech/tools/merge-pdf
- 2Click "Upload PDFs" and select your PDF files from Finder
- 3Drag the files to reorder them as needed
- 4Click "Merge PDFs"
- 5Click "Download" to save the merged file
Why this is the best option: Supports up to 20 PDFs at once. Lets you reorder files before merging. Runs entirely in your browser — no file uploads to any server, completely private.
Method 2: macOS Preview (Built-In, No Internet Needed)
Preview is macOS's default PDF viewer, and it has a hidden ability to merge PDFs using the Thumbnails panel.
Steps:
- 1Open the first PDF in Preview
- 2Go to View → Thumbnails (to show the sidebar)
- 3Open the second PDF in a separate Preview window
- 4Go to View → Thumbnails on the second window
- 5Select all thumbnail pages in the second PDF (Cmd+A)
- 6Drag those thumbnails into the sidebar of the first PDF at the desired position
- 7Go to File → Export as PDF and save the merged file
Important: Do NOT use File → Save, as this will replace the first PDF. Always use "Export as PDF" to create a new merged file.
Limitations: This method can be slow and error-prone with many files. Page ordering can be tricky with drag-and-drop. There is no way to reorder files before dragging — you must drag page by page.
Method 3: Terminal / Command Line (For Advanced Users)
If you're comfortable with the Terminal, macOS includes a Python script that can merge PDFs:
/System/Library/Automator/Combine PDF Pages.action/Contents/MacOS/join -output merged.pdf file1.pdf file2.pdf file3.pdf
Replace file1.pdf, file2.pdf etc. with your actual file paths. The merged PDF is saved as merged.pdf in your current directory.
Limitations: No visual reordering. Requires command-line familiarity. The path may differ between macOS versions.
Comparison of Methods
| Method | Ease of Use | Max Files | Reorder Support | Privacy |
|---|---|---|---|---|
| ToolFlow (Browser) | ★★★★★ | 20 | ✅ Yes | ✅ 100% local |
| macOS Preview | ★★★☆☆ | Unlimited | ⚠️ Manual | ✅ Local |
| Terminal | ★★☆☆☆ | Unlimited | ❌ No | ✅ Local |
Frequently Asked Questions
Can Preview merge password-protected PDFs? No — you need to unlock them first.
Does merging PDFs reduce quality? No — merging is lossless. The page content is copied exactly.
Can I merge a PDF and images on Mac? You can convert images to PDF first using the Image to PDF tool, then merge.
Conclusion
For most Mac users, the browser-based method is the fastest and most reliable option. Preview works well for simple two-file merges. The Terminal method suits power users who process many files programmatically.