Are my documents uploaded?

No. They are read into this browser tab and assembled there. Nothing is transmitted, which matters given that the documents people merge are usually contracts, statements and scans of identity papers.

How many files can I merge at once?

Dozens without difficulty. The practical limit is your device's memory, since every document is held while the merge runs. Very large scanned files will reach that limit sooner than small text ones.

What happens to digital signatures?

They are invalidated, necessarily. A signature attests to one specific document, and the merged file is a different document. Sign after merging rather than before.

Will mixed page sizes cause problems?

Not on screen — each page keeps its own size and viewers handle that fine. Printing a document with mixed sizes can produce unexpected scaling, so check before sending it to a print shop.

Merge PDF

Combine several PDFs into one, in the order you choose.

Everything runs inside your browser. Your files never leave your device.

Drop your files here

.pdf · they stay on this device

Ask about Merge PDF

Questions about what this tool does, which option to pick, or what it can and cannot handle.

The question you type here is sent to an AI provider to be answered — your files and whatever you put in the tool above are not, and the assistant cannot see them. Answers are generated and can be wrong. The tool itself is not guessing: it runs deterministic code on your device.

About the Merge PDF

Combining several PDFs into one is the most common thing anyone does to a PDF, and it is the reason most people end up on a file-conversion website at all. Which is unfortunate, because a PDF is very often exactly the document you should not be uploading: a signed contract, a bank statement, a medical letter, a passport scan.

This merges them in your browser. The files are read into the tab, assembled with pdf-lib, and handed back as a download. No upload step exists, so there is no retention policy to read and no server that could have kept a copy.

Order is set by dragging, and the result follows the order on screen. That matters more than it sounds, because merging is usually assembling a submission — a form, then its supporting documents, then the annexures — and the order is the structure of the submission.

What survives the merge: pages, text, images, vector content and the internal links within each document. What is lost or altered: bookmarks and outlines are rebuilt rather than preserved perfectly, form fields from multiple documents can collide if they share names, and any digital signature is invalidated. That last point is not a limitation of this tool but of merging itself — a signature attests to a specific document, and combining it with others produces a different one.

Page sizes are preserved as they are rather than normalised, so merging A4 with Letter gives a document with both. Most viewers handle that without complaint; a printer may not, which is worth checking before sending anything to a print shop.

File size is roughly the sum of the inputs. Run the result through the compression tool if it needs to go by email.

How to use it

1Drop in every PDF you want combined.
2Drag them into the order the final document should read in.
3Merge, and download the result.
4Compress the output afterwards if it needs to fit an email attachment limit.

Questions

Are my documents uploaded?: No. They are read into this browser tab and assembled there. Nothing is transmitted, which matters given that the documents people merge are usually contracts, statements and scans of identity papers.
How many files can I merge at once?: Dozens without difficulty. The practical limit is your device's memory, since every document is held while the merge runs. Very large scanned files will reach that limit sooner than small text ones.
What happens to digital signatures?: They are invalidated, necessarily. A signature attests to one specific document, and the merged file is a different document. Sign after merging rather than before.
Will mixed page sizes cause problems?: Not on screen — each page keeps its own size and viewers handle that fine. Printing a document with mixed sizes can produce unexpected scaling, so check before sending it to a print shop.