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PDFCombiner

How to merge PDFs

Fastest way on any device: drop your PDFs below, drag them into order and press Merge. Nothing is uploaded. Prefer built-in tools? The steps for Mac, Windows, iPhone and Android follow.

Drop PDFs to mergeLoading the merger…

Any device: in the browser

  1. Use the merger above, or open PDFCombiner’s merger.
  2. Drop in your PDFs, or tap the orange panel to choose them.
  3. Drag them into order; type page ranges if you only need part of a file.
  4. Press Merge. The file saves to your downloads.

Works on Windows, macOS, ChromeOS, Linux, iPhone and Android, and the files stay on the device.

How to combine PDF files on a Mac (Preview)

  1. Open the first PDF in Preview.
  2. Choose View › Thumbnails to show the sidebar.
  3. Drag the other PDF files from Finder into the sidebar, dropping them where they should go.
  4. Choose File › Export as PDF to save the combined file (plain Save changes the original).

Shortcut: select several PDFs in Finder, right-click and choose Quick Actions › Create PDF. They are combined in the order they are listed.

How to combine PDFs on Windows

Windows 10 and 11 have no built-in way to join existing PDFs. Microsoft Print to PDF can only turn one document into a PDF. Your options are a browser tool like this one, or installing a desktop app. If you install one, prefer open-source software and avoid bundled installers.

How to merge PDFs on iPhone or iPad

  1. Open the Files app and go to the folder with your PDFs.
  2. Tap ⋯ › Select and choose the files.
  3. Tap ⋯ at the bottom right and choose Create PDF. The combined file appears in the same folder.

Files uses name order; rename files with a leading number to control it, or use the browser merger for drag-to-reorder.

How to merge PDFs on Android

Android has no system-wide merge. Open this site in Chrome, pick the files from Files or Google Drive, arrange them and tap Merge.

Detailed guides by device

Password-protected and very large files

A PDF with an open password is encrypted, so no tool can merge it without that password. With it, the browser merger decrypts pages inside your tab and re-draws them; they’ll look right, but their text won’t be selectable. Big jobs are limited by memory rather than a fixed cap: if a phone struggles, merge in batches, then merge the batches.

Inside a merge, one step at a time

a.pdfPage 1Page 2Font: HelveticaLogo imagexref
merged.pdfempty
b.pdfPage 1Font: Helveticaxref

Each PDF has its own objects: pages, a content stream per page (the drawing instructions), and resources such as fonts and images. A cross-reference table (xref) records the byte offset of every object so a viewer can jump straight to it.

Why the order costs nothing to change

Order lives in one list, the page tree. That’s why dragging files around before merging is instant, and why the result isn’t re-compressed: pages are re-listed, not re-drawn.

Reordering changes the sequence while every page stays exactly as it was. The Moon’s monthly cycle has a tidier explanation than most people expect too, and ahaboo narrates why the Moon has phases.

Questions

How do I merge PDFs without Adobe Acrobat?

Use a browser tool like PDFCombiner, Preview on a Mac, or the Files app on an iPhone. None of them need Acrobat, and the browser tool works the same on Windows, ChromeOS and Linux.

Can I merge PDFs offline?

Yes. Mac Preview and iPhone Files work offline. PDFCombiner also works offline once the page has loaded, because the merging code runs in your browser rather than on a server.

Does Windows have a built-in PDF merger?

Not as such. Windows can print to PDF but doesn’t join PDFs natively. Use a browser tool, or Microsoft Edge to view and a separate tool to merge.

How do I merge password-protected PDFs?

You need the password to open each locked file. PDFCombiner asks for it and uses it only in your browser; locked pages are then re-drawn as images in the merged file, because their encryption can’t be carried over.

How do I combine PDFs on Android?

Open pdfcombiner.app in Chrome, tap the orange panel, choose the PDFs from Files or Drive, arrange them and tap Merge. The result lands in your Downloads folder.