No upload, 100% local, no account

Merge PDF files

Select your PDF files, choose the order, and download the merged document. No file is sent to a server.

How Merge PDF files works

PDF Merge combines two or more PDF files into a single document entirely inside your browser. Add your files in any order, drag the cards to rearrange them, and click to download one merged PDF. The entire operation is handled by pdf-lib running locally in your browser tab, so the pages of your contracts, signed forms, or scanned receipts are assembled on your device and never transmitted anywhere.

This matters most when the files are sensitive: employment contracts, medical referrals, legal correspondence, or any document you would hesitate to hand to an unknown online service. Because the merge runs client-side, you can disconnect from Wi-Fi after the page loads and the tool keeps working, the clearest possible proof that nothing leaves your machine.

Written by Bastien Sulyan

How to use Merge PDF files, step by step

  1. Click Add files or drag your PDFs onto the drop zone (any number of files).
  2. Drag the file cards to set the merge order; pages within each file keep their original sequence.
  3. Click Merge. pdf-lib assembles the document locally.
  4. Download the merged PDF directly from your browser.

Common use cases

  • Assembling a multi-document contract packet before sending it for signature, without sharing the individual files with a cloud service.
  • Combining monthly bank statements into a single PDF for a tax accountant.
  • Joining a cover letter, CV, and portfolio into one file for a job application.
  • Merging several scanned pages of a legal notice into a single document for archiving.

Frequently asked questions

Do my PDF files get uploaded to a server?

No. pdf-lib parses and stitches your files inside this browser tab. Each document is read into memory on your own machine, merged there, and the combined PDF is offered as a local download. To confirm it yourself, open your browser DevTools, switch to the Network tab, start the merge, and watch: no request will carry your documents.

Can I control the exact order of pages across multiple files?

You set the order at the file level by dragging the cards before merging. Pages within each file are included in their original sequence. For finer control, for example moving a single page from file 3 between pages 2 and 3 of file 1, split the files first with the PDF split tool, then merge the individual pieces in the exact order you need.

Is there a limit on how many or how large the PDFs can be?

There is no server-imposed limit. The practical ceiling is your device memory, since every page is held locally during the merge. Very large scanned files may run slowly on low-memory devices, but nothing is sent to a remote server to lift that ceiling.

Will bookmarks, hyperlinks, and form fields survive the merge?

Bookmarks and hyperlinks embedded in each source PDF are preserved by pdf-lib. Interactive form fields are included in the output but may not remain fillable in every viewer, depending on how the original form was built. For a flat, non-interactive merged file, flatten each PDF before merging.

Can I merge PDFs without installing anything or creating an account?

Yes. The tool runs entirely in your browser with no installation and no account required. There are no watermarks added, no daily quota, and no personal data collected.

Does it work when I am offline?

Yes. After the page loads once, the tool has everything it needs on your device. You can disconnect from the network and merge PDFs locally, which is also how you know for certain that your documents stay private.

Can I merge PDFs on my phone?

Yes. pdf-lib is plain JavaScript, so dropping files, reordering the cards and downloading the merged PDF all work in a mobile browser. Reordering many files by dragging small thumbnails is easier on a tablet or desktop than on a small phone screen.