Merge PDF Files
Select multiple PDFs, drag to reorder them, and click merge. 100% secure and client-side.
Drag & drop PDFs here
Files remain entirely on your device.
What is a PDF Merger?
A PDF merger combines multiple PDF files into a single document. This is useful for combining invoices, reports, scanned pages, or any documents that need to be consolidated. Our free online PDF merger lets you drag and drop multiple PDFs, reorder them visually, and merge them into one file — all processed 100% in your browser using pdf-lib. Your documents are never uploaded to any server, making it safe for confidential files.
How to Merge PDF Files Online for Free
- 1Add PDF files
Click "Add Files" or drag and drop multiple PDF files into the upload area.
- 2Reorder if needed
Drag and drop files to arrange them in your desired order.
- 3Click Merge
Click the "Merge" button to combine all PDFs into a single document.
- 4Download merged PDF
The merged PDF is generated instantly. Click "Download" to save it.
Frequently Asked Questions
Is there a limit on the number of files?
There is no hard limit on the number of PDFs you can merge. Since processing happens in your browser, the practical limit depends on your device's available memory. Most devices handle 20-50 PDFs easily.
Are my PDFs uploaded to a server?
No. DevDeck uses pdf-lib (a JavaScript library) to merge PDFs entirely in your browser. Your files never leave your device — this is safe for confidential legal documents, financial records, and personal files.
Does merging preserve formatting?
Yes. PDF merging preserves all original formatting including text, images, links, bookmarks, and page layouts. It simply combines the pages into a single file.
Can I merge password-protected PDFs?
Currently, password-protected PDFs must be unlocked before merging. You can use our Protect PDF tool to add password protection after merging.
Why Use DevDeck?
Most PDF merging websites upload your files to their servers — a major privacy concern for sensitive documents. DevDeck merges PDFs 100% in your browser using pdf-lib. Your contracts, invoices, and personal documents never leave your device.