Merge PDF Files

Combine multiple PDFs into one document locally in your browser. Fast, free and 100% private — files never leave your computer.

You can merge PDF files without uploading them by combining the documents locally in your browser, so the merged file is built on your own machine.

Merging is the most common PDF task there is, and it is also the one people most often do with sensitive material: an invoice pack, a signed agreement plus its exhibits, a set of bank statements for a mortgage application. Every one of those is a document you would rather not post to a stranger's server.

PDF Vault combines the files in browser memory. Page order is whatever you drag it to be, the output is a single clean PDF, and the whole operation typically finishes in under two seconds because there is no upload or download round-trip.

Nothing you do here is uploaded. The file is read into your browser's memory, processed by WebAssembly on your own machine, and written straight back to your downloads folder. You can confirm it yourself: open DevTools, switch to the Network tab, and run the tool — there is no request carrying your document, because there is no server endpoint to receive it.

How to merge PDF files offline

  1. Drop every PDF you want combined onto the tool, or select them from your file picker.
  2. Drag the files into the order you want them to appear in the final document.
  3. Remove anything you added by mistake with the delete control on each row.
  4. Click merge, and the combined PDF downloads immediately to your device.

What you get

  • Unlimited page count. Combine two files or fifty; the only ceiling is your machine's memory.
  • Drag to reorder. Set the exact sequence before merging instead of fixing it afterwards.
  • Keeps quality. Pages are copied, not re-encoded, so text stays sharp and file size stays sensible.
  • No queue. Nothing waits in line behind other people's jobs, because the work happens on your computer.

Frequently asked questions

How many PDFs can I merge at once?

As many as your browser can hold in memory. Dozens of ordinary documents is routine; the practical limit shows up with very large scanned files.

Will merging reduce the quality of my pages?

No. Pages are copied across as-is rather than re-rendered, so text stays vector-sharp and images keep their original resolution.

Can I merge a password-protected PDF?

Remove the password first with the Unlock tool (you need the current password), then merge the unlocked file.

Does merging strip the original metadata?

The merged file carries minimal metadata. If you want to be certain nothing identifying survives, run the result through the Sanitize tool before sharing it.

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