Merge PDF
Choose two or more PDFs, reorder them if needed, then merge. Every byte stays on your device — nothing is uploaded to a server.
How merging works without a server
Each PDF you choose is read locally as raw bytes, then handed to pdf-lib, a JavaScript library that understands the
PDF file format well enough to open a document and copy its pages
into a new one. For every source file, in the order you set, this
tool copies each page's real content — not a picture of the page —
into a fresh, empty PDF document. Once every source file has been
copied in, the merged document is packaged into a downloadable
file with Blob and a browser download link. At no
point does a file cross the network.
Worked example
Say you have invoice-jan.pdf (2 pages) and invoice-feb.pdf (3 pages). Select both, leave the order as-is (January first), and merge — you get one 5-page PDF with January's two pages followed by February's three, in their original layout and quality. Move February above January with the ↑ button first, and the merged file's page order flips to match.
Frequently asked questions
Are my PDFs uploaded anywhere?
No. Every file you choose is read locally with the browser's File API, and a library called pdf-lib runs entirely in your browser tab to build the merged document. Nothing is sent to a server, so private or confidential PDFs never leave your device.
Can I change the order the files are merged in?
Yes — after you choose your files, use the ↑ and ↓ buttons next to each one to move it up or down the list before merging. The final PDF follows the list order top to bottom.
Does merging lose any quality, text, or links?
No. pdf-lib copies each source PDF's actual page content — the underlying vector graphics, text, and embedded images — directly into the new document. It doesn't rasterize pages into flat images, so selectable text stays selectable and nothing is re-compressed or degraded.
Is there a limit on file size or number of PDFs?
The only real limit is your browser's available memory, since everything happens on your device rather than a server. Typical documents — even a dozen multi-page PDFs — merge in well under a second; very large scanned PDFs (hundreds of megabytes) may be slower.