Are my PDF files uploaded to a server?

No. Every operation runs entirely inside your browser using the pdf-lib library. Your files are never sent to any server, so you retain complete privacy and control.

How many PDFs can I merge at once?

There is no hard limit. Practical limits depend on your device's available memory — most modern devices handle dozens of PDFs comfortably.

Does merging preserve bookmarks, hyperlinks, and form fields?

pdf-lib copies page content faithfully, but interactive features such as bookmarks, JavaScript actions, and AcroForm fields may not be preserved in the merged output.

Can I reorder the files before merging?

Yes. Use the Move Up / Move Down buttons in the file list to arrange your PDFs in the desired order before clicking Merge.

What browsers are supported?

Any modern browser supporting the File API and Blob URLs — Chrome, Edge, Firefox, and Safari all work. No plugins or extensions needed.

Merge PDF

PDF Tools· 4 tools

Free online PDF merger. Upload two or more PDF files, drag to reorder them however you like, then click Merge to combine them into a single downloadable PDF. No account required, no file size limits imposed by a server, and — most importantly — your files never leave your device. 100% client-side using pdf-lib.

Drop PDF files here or click to browse

Files never leave your browser

Privacy: All processing happens entirely in your browser using pdf-lib. Your PDF files are never uploaded to any server.

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