Everything runs on your machine — your input is processed right here in your browser and never uploaded to any server.

Merge PDF

About this tool

Combining PDFs is one of those small tasks that comes up constantly: stitching a signed page back into a contract, assembling scanned receipts into one expense report, or packaging several chapters into a single document to send. This tool merges any number of PDF files into one, in the order you choose, without your documents ever leaving the browser.

Unlike most online mergers, nothing here is uploaded. The files are read and combined by the pdf-lib engine running as JavaScript inside your own tab, which makes it safe to merge contracts, medical records, and other documents you would never hand to an unknown server.

How to use

  1. Click "Add PDF files" and select two or more PDFs (you can add more later).
  2. Arrange the files with the up and down arrows — the merged PDF follows this order.
  3. Remove any file added by mistake with the ✕ button.
  4. Press "Merge & download" and the combined PDF saves to your device.

Your documents are never transmitted anywhere. Reading, merging, and saving all happen inside your browser tab, so confidential files stay entirely on your machine.

Frequently asked questions

Is there a limit on how many PDFs I can merge?

There is no fixed limit. Because everything runs in your browser's memory, very large collections are bounded by your device rather than by any server quota; merging dozens of ordinary documents works fine.

Will the merged PDF keep the original quality?

Yes. Pages are copied into the new document as-is, without re-rendering or recompression, so text stays sharp and selectable and images keep their original resolution.

Can I merge password-protected PDFs?

Encrypted files that require a password to open cannot be merged. Remove the password first using the software that created the file, then merge the unlocked copies.