Merge PDF Files Online into One Document

This tool gathers several PDFs into a single document: choose or drop the files, they are appended in that order, and the result is one merged.pdf. The work is done with pdf-lib inside the browser, so your invoices, contracts or papers are never stored on a server. File names and sizes are listed before merging, and a broken file shows an error right there. It suits attaching appendices to a report, joining sections of one document, or producing a single file to hand over.

This tool runs entirely in your browser. No data is sent to any server.

How to use it

1. 1

   Select all the PDFs at once, or drop them into the box.

2. 2

   Check the order in the list; they are appended in the order you selected them.

3. 3

   Press merge and merged.pdf downloads immediately.

Frequently asked questions

How do I change the order of the files?

This version keeps the selection order and does not offer drag-reordering. Pick the files one by one in the order you want, or reorder pages in a PDF editor afterward.

Are the files uploaded?

No. Reading and writing the PDFs happens entirely in the browser; the files never leave your device and nothing is left behind to clean up on a server.

Is there a file size limit?

There is no fixed cap; the real limit is browser memory. Files of several hundred megabytes can be slow or crash the tab.