Combine PDF files on a Mac
macOS can join PDFs with built-in tools. Use the merger below when you want drag-to-reorder, page ranges or bookmarks without fiddling with Preview’s sidebar.
Drop PDFs to mergeLoading the merger…
With Preview (built in)
- Open the first PDF in Preview.
- Choose View › Thumbnails.
- Drag the other PDFs from Finder into the thumbnail sidebar, where they should appear.
- Choose File › Export as PDF to save a combined copy (plain Save overwrites the first file).
Faster for whole files: select the PDFs in Finder, Control-click, Quick Actions › Create PDF. They are joined in the order they are listed in Finder.
With the browser merger above
- Tap or click the orange panel and choose your PDFs (images work too).
- Drag them into order; type a page range under any file to take only part of it.
- Press Merge. The new PDF saves to your downloads, built on this Mac.
Tips for Mac
- To merge only some pages in Preview, select thumbnails in one window and drag them into the other window’s sidebar.
- Preview drops bookmarks from the source files; the merger here can add one bookmark per file.
- Safari, Chrome and Firefox on macOS all run the browser merger.
What carries over
| Situation | What happens here |
|---|---|
| Ordinary PDFs | Pages are copied as-is: text stays selectable, links on the page keep working, images are not re-compressed. |
| Password to open | You type the password; it is used only in this tab. The output can't carry the old encryption, so those pages are re-drawn as images (about 144 dpi) and their text is no longer selectable. |
| Owner password only (no-edit / no-print flags) | Opens without asking, but is handled the same way as above: pages become images. We don't strip protection and hand back an editable copy. |
| Very large jobs | Everything is held in this tab's memory. A laptop copes with a few hundred MB; phones and tablets top out sooner. If a tab crashes, merge in batches and then merge the results. |
| Fillable forms | Field appearance is kept, but fields may stop being fillable in the merged file. Fill and save forms first. |
| Digital signatures | Any change to a signed PDF breaks the signature's validation. Merge copies if you need the signed original intact. |
| Original bookmarks | Not carried over. The merger can add one bookmark per file instead. |
Questions
Does Preview reduce PDF quality when merging?
Not when you use Export as PDF with the Quartz filter set to None. Choosing “Reduce File Size” re-compresses images.
Why did Quick Actions put my files in the wrong order?
Create PDF follows the current Finder sort. Sort by name, or rename files with a leading number (01, 02…) before selecting them.
Can I merge PDFs on a Mac without Preview?
Yes. This browser tool works offline once loaded and never uploads the files.