How to merge PDFs on your Mac

You don't need a website to merge PDFs on a Mac. Finder can join files into one PDF, Preview can move pages and whole files between PDFs, and Koi merges them in one drag with the order in front of you. None of them uploads your files.

We make Koi, so read this with that in mind. Everything about Koi here is what version 1.12 does. Finder's and Preview's steps come from Apple's own guides, checked October 20, 2026.

1. Select the PDFs in Finder, in the order you want them. They go in the order you select them.
2. Control-click the selection and choose Quick Actions, then Create PDF.
3. A new PDF appears beside them, named after the first one you picked.

The Create PDF button at the bottom of Finder's Preview pane does the same. Apple's guide covers both.

1. Open the PDF you want to add to, and turn on thumbnails in its sidebar.
2. Drag another PDF's icon from Finder onto that sidebar to add all of it, or drag single pages over from the other PDF's sidebar.
3. Close the file. Preview saves the change into it.

Preview changes the file you opened, so Apple suggests File, Duplicate first if you want to keep the original. Apple's guide has the details.

1. Select the PDFs in Finder and start dragging them.
2. While you're still holding them, press and hold Shift. A wheel opens round your pointer, “3 PDFs” in its middle.
3. Drop them on Merge. Merge PDFs opens with every file in Finder's order.
4. Move any of them up or down, take one out, or add more with Add PDFs.
5. Click Merge PDFs. “First merged.pdf” lands beside them and shows in Finder.

• The originals are never touched, so there's nothing to duplicate first.
• When the folder can't be written to, the copy goes to Downloads.
• A PDF a password keeps shut doesn't open.

The same wheel splits a PDF into a file for every page, or for ranges you type like 1-3, 4, 5-. Organize lets you drag its pages into a new order, turn them, copy them or take them out. It also compresses a PDF and converts one to Word, Excel or pictures. More on the Shift wheel.

Finder and Preview are free and already on your Mac. Koi has no free plan: Pro is $20 a month, or $192 a year, after a 3-day free trial that needs a card. Lifetime is paid once, from $59. The Shift wheel uses no AI, so it never counts against Koi's usage. See the plans.