Merge PDF
Combine several PDF files into one, in the order you choose.
Drop the PDFs you want to combine
Add two or more files — they are merged in your browser, never uploaded
About Merge PDF
Merging PDFs is the most requested PDF operation, and almost every free option online asks you to upload confidential documents to a server you know nothing about.
This tool loads each file into memory in your browser, copies the pages into a new document in the order you set, and hands you the result as a download. Nothing is transmitted.
How Merge PDF works in your browser
Each file you select is read with the File API into an ArrayBuffer — a copy in your tab’s memory. The PDF structures are parsed there, the page objects from every document are collected in order, and a new PDF is assembled and handed back as a blob your browser downloads. The files are never sent anywhere.
Merging copies page content along with the resources each page references — fonts, embedded images and vector graphics — so pages look the same in the merged file as they did in the originals. Document-level features that cannot be meaningfully combined, such as form field values and digital signatures, do not survive a merge; a signature covers a specific document, and a merged file is a different document.
Because everything is held in memory, the practical limit is your device’s RAM rather than a server-side upload cap. Very large scanned documents on a phone are the case most likely to run out of room.
When to use it
- Combining scanned pages into one document for an application or a claim.
- Merging invoices or receipts into a single file for an expense submission.
- Assembling separately exported chapters or reports into one deliverable.
- Joining documents containing financial, medical or legal information — exactly the files that should not be uploaded to a free web service.
Frequently asked questions
Are my PDFs uploaded?
No. Merging happens in your browser using a JavaScript PDF library. The files never leave your device.
Is there a file size limit?
Only the memory available to your browser tab. Very large scanned documents may be slow but generally work.
Are bookmarks and forms preserved?
Page content, images and text are preserved. Interactive form fields and bookmarks are not carried across.