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PDF Merger

In-browser only Files never uploaded Lossless merge
Merged in your browser — your files never leave your device. Powered by pdf-lib.

Your merged PDF will download automatically once you merge.
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Overview

Combine PDF files into one in your browser

Pull scattered PDFs — scanned pages, report sections, invoices — into one ordered document. Set the sequence, then merge and download, all on your device.

  • Merges multiple PDFs into one file
  • Reorder files before you merge
  • Pages are copied exactly — no re-rendering or recompression
  • Password-protected files are detected and flagged
  • Runs entirely in your browser — no uploads
  • Files are read and merged in your browser
  • Nothing is uploaded to a server
  • Encrypted and corrupt PDFs are detected locally
  • The merged PDF is built and downloaded on your device
  • Powered by the pdf-lib library
  • Combine scanned pages into one document
  • Assemble a report from separate PDF sections
  • Merge invoices or receipts for filing
  • Join contract pages before sending
  • Bundle chapters into a single ebook PDF

Step by step

How to merge PDF files

  1. 1
    Add your PDF files

    Drag PDF files onto the upload area, or select Browse files to pick them from your device. You can add up to 30 files.

  2. 2
    Set the order

    Use the up and down arrows to arrange the files. They are merged top to bottom — each file keeps all of its pages.

  3. 3
    Merge and download

    Select Merge PDFs. The combined PDF is built locally and downloads automatically as merged.pdf.

Get the best result

Tips for a clean merge

  • Order files before merging

    Files are combined in the order shown, top to bottom. Arrange them with the up and down arrows before you press Merge.

  • Unlock protected files first

    Password-protected PDFs are flagged with a lock icon and cannot be merged. Remove the protection in your PDF viewer, then re-add the file.

  • Quality is preserved

    Pages are copied as-is — text, images, and fonts are not re-rendered or re-compressed, so the merged PDF matches the originals.

  • Large queues need memory

    Merging runs on your device. Very large files or long queues use more memory and take longer on low-end devices.

Frequently asked questions

How do I merge several PDF files into one?
Add your PDF files to the upload area, set their order with the up and down arrows, then select Merge PDFs. You get one combined PDF downloaded as merged.pdf.
Are my files uploaded to a server?
No. Files are read and combined entirely in your browser using pdf-lib. You can confirm there are no outbound requests in your browser's Network tab.
Does merging reduce PDF quality?
No. Pages are copied exactly with pdf-lib — text, images, and fonts are not re-rendered or re-compressed, so the merged PDF matches the source files.
Can I change the order of the files?
Yes. Each file in the list has up and down arrows. Files are merged in the order shown, from top to bottom.
Can I merge password-protected PDFs?
Encrypted PDFs are detected when you add them and flagged with a lock icon. Remove the password protection in your PDF viewer first, then re-add the file. The tool never attempts to bypass protection.
Is there a limit on file size or number of files?
You can add up to 30 PDF files per merge. Because merging runs in your browser, very large files use more memory and take longer.
Can I merge PDFs on my phone?
Yes. The layout works on phones with large touch targets, and the merge runs in any modern mobile browser.