Merge PDF

How the PDF merger works

When you add a file, the tool reads it in your browser to count its pages and to check that it can be opened. When you press “Merge PDFs”, it creates a new PDF and copies every page of every file into it, in the order of the list. The copying is done by pdf-lib, a JavaScript PDF library, usually in a background thread of your browser, so the page stays responsive while large files are merged.

The pages are copied as they are. Nothing is converted to images or drawn again, so text stays sharp and searchable, and the merged file is usually about as large as the files you added put together.

What is kept and what is not

Kept in the merged PDF:

• Page content: text, images, vector graphics and fonts.
• Page size and orientation, including rotated pages. Files with different page sizes can be merged; every page keeps its own size.
• Links and comments on the pages. A link that jumps to another page of the same file still works after merging.

Not kept:

• Bookmarks (the outline panel in PDF readers) and the document title of the original files.
• Fillable form fields may stop being editable. Text that was already filled in usually stays visible.
• Digital signatures. A signature only covers the file that was signed, so it is not valid in a merged copy.

Password-protected PDFs

A PDF that asks for a password when you open it has to be unlocked first. Open it with the password in a PDF app, save a copy without the password, and add that copy. Some PDFs open without a password but carry an owner password that restricts editing or printing. This tool does not remove such restrictions, so those files are refused with an explanation. PDFs that are encrypted but allow everything are merged normally.

Privacy

Your files are processed by JavaScript on your own device. They are not uploaded to a server, so you can use the tool for private documents such as bank statements or ID proofs. Nothing is stored after you close the page.