The PDF corner

Merge PDFs into one

Drop your PDFs in together. The tool stacks them end to end in the order you can see on screen, and hands you back a single file. None of the documents ever leaves your device.

.pdf80 MB per file dropped

Drop your PDFs hereAt least two files, all at once. Nothing will be sent: the assembly happens here, on your device.Choose a file

This file is beyond what this tool does

This tool needs JavaScript to work, and that is precisely because it works ON YOUR DEVICE: without JavaScript, your file would have to be sent to a server. The instructions and the limits of the tool, however, can be read without JavaScript, just below.

How this is built

Your file never leaves your device

This tool works entirely inside your browser. Not one byte of your file is sent anywhere, and nothing is kept once the tab is closed.

Checkable in ten seconds, without taking our word for it:

Open your browser's inspector: the F12 key (or Ctrl+Shift+I, or Cmd+Option+I on a Mac).
Go to the “Network” tab, then clear the list.
Process a file on this page. The list stays empty: no request goes out.
To go further: cut your connection and do it again. The tool still works.

This absence of requests is also checked BY MACHINE before every release: a lock drives a real browser, processes a real file, and refuses to publish if a single byte goes out.

The proof page, step by step and in pictures

Going further

InstructionsHow it works

PDFs only, and that is deliberate: putting an image into a PDF is a different gesture with settings of its own. The “Images to PDF” tool in the same corner handles that.

VerifyThe proof, step by step

The network inspector check, explained one gesture at a time, with screenshots.

The cornerThe PDF corner

The other tools in this corner of the workshop.

UnderstandHow this is built

The formats actually handled, browser by browser, and what we ruled out.