Preview on Mac can merge PDFs by dragging thumbnails between windows, but the workflow is fragile: page order gets scrambled, encrypted PDFs refuse to combine, and password-protected files silently fail.
Merge PDF runs in Safari, Chrome, or Firefox directly — no installer, no Rosetta issues on Apple Silicon, and no upload. You get a single combined PDF with the exact page order you set.
How to use Merge PDF on Mac
- Open Merge PDF in Safari, Chrome, or any modern Mac browser.
- Drag your PDF files from Finder into the drop zone.
- Reorder pages by dragging thumbnails until the sequence matches what you want.
- Click Merge, then choose Save As to store the combined PDF anywhere on your Mac.
Tips that actually matter for this case
- On Apple Silicon Macs, browser-based tools skip the Rosetta translation layer entirely, so merging is faster than Preview for large files.
- If a file won't drop in, check that it isn't password-protected — unlock it with Unlock PDF first.
- Preview's default save format uses Quartz filters that can bloat the output. Merge PDF writes cleaner byte-level output.