Merge PDF Files Online — Free & Private

Billu's PDF Merger combines multiple PDF documents into a single file using pdf-lib, running entirely in your browser. Drag in your PDFs, reorder them by dragging rows up or down, and download your merged document instantly.

Use PDF Merger →

Common use cases

Combine chapters into a single ebook
Merge invoices into one PDF for accounting
Assemble a portfolio from separate documents
Combine scanned pages into one file

Frequently Asked Questions

Are my PDFs uploaded anywhere?

No. pdf-lib runs in your browser. Your files never leave your device.

Is there a file size limit?

There is no server-side limit. Very large files may be slow depending on your device RAM.

Do password-protected PDFs work?

Not currently. Unlock your PDFs first before merging.