If you need to merge PDF files on Mac, you probably don’t need to install anything. macOS has built-in tools that handle this surprisingly well. I spent a week testing every method I could find – native macOS features, free apps, online tools, and even Terminal commands – and here’s what actually works in 2026.
Before diving into specifics, check out our full roundup of the best free PDF editors if you need more than just merging. And if you want platform-agnostic options, our guide on how to combine PDF files for free covers online tools that work on any device.
Quick Comparison: Mac PDF Merge Methods
| Method | Max File Size | Batch Merge | Page Reordering | Offline | Best For |
|---|---|---|---|---|---|
| Preview (built-in) | No limit | Yes | Yes | Yes | Most users |
| Finder Quick Actions | No limit | Yes | No | Yes | Fast bulk merges |
| Terminal (Python) | No limit | Yes | Manual | Yes | Automation/scripting |
| iLovePDF | 100 MB free | Yes (25 files) | Yes | No | Quick one-off merges |
| Smallpdf | 5 MB free | Yes | Yes | No | Simple interface |
| PDFsam Basic | No limit | Yes | Yes | Yes | Power users who merge often |
| PDF24 Online | No limit | Yes | Yes | No | No signup needed |
Method 1: Use Preview (Built Into Every Mac)
Preview is the fastest way to merge PDFs on a Mac. No downloads, no accounts, no file size limits. It ships with macOS and honestly does a better job than most paid apps I’ve tried.
Step-by-step:
- Open the first PDF in Preview (double-click it – Preview is the default PDF viewer on Mac)
- Click View > Thumbnails in the menu bar (or press Option + Command + 2) to show the sidebar with page thumbnails
- Select the thumbnail where you want to insert the second PDF – click the page after which the new pages should appear
- Go to Edit > Insert > Page from File
- Select the second PDF and click Open
- The pages from the second PDF appear in the thumbnail sidebar. Drag them around to reorder if needed
- Save with File > Export as PDF (not just Save – more on this below)
One gotcha that tripped me up: if you just hit Command+S, Preview saves over the original file. Use Export as PDF instead to create a new merged file and keep your originals intact. I learned this the hard way after overwriting a contract I needed to keep separate.
Merging more than two PDFs in Preview
You can repeat the Insert step for each additional PDF. Or here’s a faster approach: open the first PDF with thumbnails showing, then drag additional PDF files directly from Finder into the thumbnail sidebar. Drop them at the position where you want them. This works with multiple files at once – select them all in Finder and drag as a batch.
Preview handles files of any size since everything runs locally on your Mac. I’ve merged 200+ page documents without issues on an M2 MacBook Air with 8GB RAM.
Method 2: Finder Quick Actions (Fastest for Bulk Merges)
This one most people don’t know about. Since macOS Mojave (10.14), Finder has a built-in “Create PDF” quick action that merges multiple PDFs into one.
How to use it:
- Open Finder and navigate to the folder containing your PDFs
- Select all the PDF files you want to merge (Command+click or Shift+click)
- Right-click the selection
- Choose Quick Actions > Create PDF
- macOS creates a merged PDF in the same folder
The merged file appears almost instantly for small documents. The files are combined in alphabetical order by filename, so if order matters, rename your files with number prefixes first (01_intro.pdf, 02_chapter1.pdf, etc.).
The downside: you can’t reorder pages or pick specific pages from each PDF. It’s all-or-nothing. For more control, use Preview or one of the other methods below.
Method 3: Terminal with Python (For Automation)
macOS comes with Python 3 pre-installed (on recent versions). If you merge PDFs regularly or need to script it, the pypdf library makes this trivial.
One-time setup:
pip3 install pypdfMerge command:
python3 -c "
from pypdf import PdfWriter
merger = PdfWriter()
for f in ['file1.pdf', 'file2.pdf', 'file3.pdf']:
merger.append(f)
merger.write('merged.pdf')
merger.close()
"Replace the filenames with your actual files. You can also use glob patterns to merge everything in a folder:
python3 -c "
import glob
from pypdf import PdfWriter
merger = PdfWriter()
for f in sorted(glob.glob('*.pdf')):
merger.append(f)
merger.write('merged_output.pdf')
merger.close()
"This processes files locally with no size limits and no internet connection needed. I use this approach for a monthly report that combines 15-20 PDFs from different departments. Takes about 2 seconds for ~300 pages total.
Method 4: iLovePDF (Online, No Install)
When I’m on someone else’s Mac or don’t want to mess with Preview’s sidebar, iLovePDF is my go-to online option. The free tier lets you merge up to 25 PDF files at once with a combined limit of 100 MB.
How it works:
- Go to ilovepdf.com/merge_pdf
- Upload your PDF files (drag and drop works)
- Reorder by dragging thumbnails
- Click “Merge PDF”
- Download the result
Processing is fast – a 50 MB merge finished in about 8 seconds during my tests. Files are deleted from their servers after 2 hours according to their privacy policy. The free plan limits you to 2 tasks per hour, which is plenty for occasional use.
If you’re looking for more online PDF tools, our guide to compressing PDFs on Mac covers several of the same services.
Method 5: Smallpdf (Simple but Limited Free Tier)
Smallpdf has a clean interface and works well, but the free version now restricts you to 5 MB per file and 2 tasks per day. That’s a tight limit if your PDFs contain images or scans.
Steps:
- Visit smallpdf.com/merge-pdf
- Drop your files onto the page
- Arrange the order
- Click “Merge PDF!”
- Download the result
The drag-and-drop reordering is smoother than most competitors. But honestly, the 5 MB cap on the free tier makes this hard to recommend when iLovePDF gives you 100 MB. Smallpdf Pro costs $9/month if you need unlimited access.
Method 6: PDFsam Basic (Free Desktop App)
PDFsam Basic is open-source, runs offline, and has zero file size restrictions. If you merge PDFs every week, this is worth installing.
What you get:
- Merge unlimited PDFs with drag-and-drop ordering
- Select specific page ranges from each file (e.g., pages 1-5 from document A, pages 10-15 from document B)
- Add blank pages between documents
- Include or exclude bookmarks from the originals
- Generate a table of contents in the merged file
Download it from pdfsam.org. The Basic version is completely free. They also sell PDFsam Enhanced ($69/year) with editing features, but for merging you don’t need it.
One thing to note: PDFsam Basic requires Java Runtime. The installer bundles it, so you don’t need to install Java separately, but the app is about 150 MB total because of this.
Method 7: PDF24 Online (No Account Required)
PDF24’s web tool doesn’t require signup or login. You upload your files, merge them, and download the result. That’s it.
How to use it:
- Go to tools.pdf24.org/en/merge-pdf
- Add your PDF files
- Rearrange the order if needed
- Click “Merge” and download
PDF24 claims all processing happens in your browser (client-side) for files under 100 MB. Larger files get uploaded to their servers and deleted after 1 hour. I tested this with browser dev tools open and can confirm small files don’t generate upload network requests.
No file size limit, no daily task limit, no account. The catch? The interface is cluttered with ads on the free version. But functionally it works perfectly.
Which Method Should You Use?
For most people: Preview. It’s already on your Mac, handles any file size, and lets you reorder pages. There’s genuinely no reason to install anything else for occasional PDF merging.
For quick bulk merges without reordering: Finder Quick Actions. Two clicks and done.
For automation or recurring merges: Terminal with Python. Set it up once, run it whenever.
For when you’re not on your own Mac: iLovePDF or PDF24. Both work in any browser with generous free limits.
For heavy, regular use with page-range control: PDFsam Basic. Open-source, offline, no limits.
Tips for Better PDF Merges on Mac
Keep file sizes manageable
If your merged PDF ends up huge, compress it afterward. Preview’s Export as PDF dialog has a “Quartz Filter” dropdown where you can select “Reduce File Size.” It’s aggressive though – image quality drops noticeably. For better compression control, check our Mac PDF compression guide.
Preserve original files
Always use “Export as PDF” in Preview, not “Save.” The Save option overwrites your source file. If you’re merging documents you might need individually later, make copies first or use Export.
Check the merged result
After merging, scroll through the entire document. I’ve seen cases where landscape pages from one PDF get rotated to portrait in the merged output, especially with online tools. Preview and PDFsam handle mixed orientations correctly in my testing.
Large merges and memory
Preview loads the entire PDF into RAM. If you’re merging a 500-page document with lots of images, your Mac might slow down with 8GB RAM. PDFsam and the Terminal method handle large files more efficiently because they process pages sequentially without loading everything at once.
Common Issues and Fixes
“Create PDF” missing from Quick Actions
If you don’t see the option when right-clicking, go to System Settings > Privacy & Security > Extensions > Finder and make sure Quick Actions are enabled. On older macOS versions, this is under System Preferences > Extensions.
Preview won’t let me drag PDFs into the sidebar
Make sure you’re viewing Thumbnails (View > Thumbnails), not Table of Contents or Contact Sheet. Only the Thumbnails view supports drag-and-drop insertion.
Merged PDF has wrong page order
In Preview, drag thumbnails to rearrange after merging. In Finder Quick Actions, rename files with number prefixes before merging. In online tools, use the drag-to-reorder feature before clicking merge.
Output file is much larger than the combined originals
Some tools (including Preview) can inflate file size when merging because they re-encode images. Run the output through a PDF compressor afterward. PDF24 and iLovePDF both have compress tools alongside their merge features.
FAQ
Can I merge PDF files on Mac without installing anything?
Yes. Preview comes pre-installed on every Mac and can merge unlimited PDFs. Open the first PDF, show thumbnails (View > Thumbnails), then go to Edit > Insert > Page from File to add more PDFs. You can also use Finder Quick Actions – select multiple PDFs, right-click, and choose Quick Actions > Create PDF.
Is the Preview app on Mac really free for PDF merging?
Preview is included with macOS at no extra cost. There are no hidden limits, no watermarks, and no file size caps. Apple doesn’t charge for any Preview features. It handles merge, split, annotate, sign, and basic editing all for free.
What’s the fastest way to merge PDFs on Mac?
Finder Quick Actions is the fastest method. Select your PDF files in Finder, right-click, choose Quick Actions > Create PDF. The merged file appears in the same folder within seconds. The files are combined in alphabetical order by filename.
Can I merge password-protected PDFs on Mac?
Preview can open and merge password-protected PDFs if you enter the password when opening each file. The merged output won’t be password-protected unless you explicitly add protection. For batch merging of protected files, PDFsam Basic can handle this with a password field per file.
How many PDF files can I merge at once on Mac?
Preview and Finder have no practical limit – I’ve tested merging 50+ files without problems. Online tools like iLovePDF cap at 25 files per merge on the free plan. PDFsam Basic has no file count limit. The real constraint is your Mac’s available RAM when working with very large documents.