How to Combine PDF Files on a Mac (Built-In + Free Tools)
On a Mac, you can combine PDFs using Preview's built-in thumbnail sidebar (open one PDF, drag additional PDFs into the sidebar, then export), or faster: open the Merge PDF tool in Safari or Chrome, upload your files, reorder them, and download the combined PDF — no need to open Preview at all.
Method 1: Preview (built into macOS)
1. Open the first PDF in Preview and show the thumbnail sidebar (View > Thumbnails).
2. Drag additional PDF files directly into the sidebar at the position you want them.
3. Go to File > Export as PDF to save the combined document.
This works well for two or three files but gets fiddly once you're combining many documents or need to reorder pages precisely.
Method 2: A browser-based merge tool
1. Open the Merge PDF tool in Safari or Chrome.
2. Select all the PDFs you want to combine at once.
3. Drag to reorder them in the list.
4. Merge and download — the combined file is generated locally, without opening a separate app.
This scales better for combining many files and gives a clearer view of the final page order before you commit.