Merge PDF

Combine multiple PDF files into a single document, right in your browser.

About this tool

Select two or more PDF files and combine them into a single document, in the order shown below (use the arrows to reorder them first). Everything runs locally in your browser using the open-source pdf-lib library — your files are never uploaded anywhere.

Frequently asked questions

Is there a file size or page limit?
No hard limit, but very large PDFs (hundreds of MB) may be slow or run out of memory, since everything is processed in your browser's memory rather than on a server.
Are my files uploaded anywhere?
No — merging happens entirely on your device. Nothing is sent to any server.
What if one of my PDFs is password-protected?
Encrypted PDFs generally can't be read by this tool and will show an error — remove the password first (e.g. in Adobe Acrobat or your PDF reader) and try again.