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Merge PDFs without uploading them.
The merge happens in this tab. Photos can go in too.
Why this is worth caring about
Merging is the most ordinary thing anyone does to a PDF, and it is almost always for a dull reason: an expense claim needs every receipt in one file, a broker asked for six months of statements as a single attachment, a scanned contract arrived in four parts.
Notice what those have in common. Nobody merges a restaurant menu. The documents that need combining are the ones with account numbers, salaries, addresses, and signatures on them — and the standard way to combine them is to upload the entire set to a website.
The architectural difference
A server-based merge tool has to receive your documents before it can do anything with them. That is not a failing of any particular company; it is what the model requires. Retention limits and encryption at rest are real mitigations, but the file has still left your control.
Here, pdf-lib is downloaded to your browser and runs there. Each document is parsed in the tab, its pages are copied into a new document, and you get the bytes back as a download. There is no endpoint in the code that could receive a file, which is what makes the claim checkable rather than promised.
Watch nothing leave
Open DevTools → Network → run a conversion. There is no upload endpoint to receive a file.
What survives the merge
Page content, embedded fonts, page sizes, and rotation all carry across, so text stays selectable and images keep their original compression. Bookmarks, form fields, and annotations do not — those live in structures a simple page copy cannot preserve, and pretending otherwise would produce files that look right and behave wrong.
Photographs can go in alongside the PDFs. Images become pages in the same document, decoded on your device, and iPhone HEIC photos work without any codec installed.
The usual next steps
- Compress PDF if the combined file is too large to email — see also shrinking a PDF for email
- Organize PDF to reorder or drop pages once everything is in one file
- Add Page Numbers to PDF if someone needs to reference pages
Before you email a stack of PDFs, drop them here.
Common questions
Can I merge PDFs without uploading them?
Yes. This page runs the merge in your browser with pdf-lib. No request carries the file, which you can confirm in the Network panel of developer tools.
Is there a limit on how many files I can merge?
No fixed limit. The practical ceiling is your device memory, since every document is held in the tab while it works.
Does merging reduce quality?
No. Pages are copied as objects rather than re-rendered, so nothing is recompressed and text stays selectable.
Can I merge photos and PDFs together?
Yes. Drop images in with the PDFs and they become pages in the same document, decoded on your device. HEIC photos from an iPhone work too.
What about a password-protected PDF?
Unlock it first with Unlock PDF, then merge the unlocked copy. An encrypted file cannot have its pages read until it is decrypted.
Tools on this page
- Merge PDF — Combine PDFs in any order, in this tab.
- Compress PDF — Shrink a PDF for email without sending it anywhere.
- Organize PDF — Reorder, delete, and rotate pages visually.
- Image to PDF — JPG, PNG, WebP, HEIC, AVIF — one PDF.