About this tool
Merge PDF joins several PDF files into one, in whatever order you put them. Drag the file cards until the order is right — the card at the top becomes page one — then press Merge. You get a single file back.
Your files never leave your computer. The merging happens inside your browser, on your own device. Nothing is uploaded, nothing is stored, and nothing is deleted afterwards because nothing was ever sent. You can watch this yourself: turn off your internet after the page has loaded and the tool still works.
What survives the merge
A merged PDF here is a real PDF, not a picture of one. Specifically:
- Text stays text. You can still select it, copy it and search it in the merged file. Many online mergers flatten pages into images; this one does not.
- Links keep working. Clickable web links inside your documents still click.
- Bookmarks carry over from each source file.
- Page sizes stay as they were. If one file is A4 and another is Letter, each keeps its own size inside the merged file. Nothing is stretched or cropped to match.
That last point surprises people, so it is worth being clear about: merging does not force every page to one size. If you need a single consistent size for printing, set that in your printer dialog, or build the document from images with JPG to PDF, where you choose the page size.
How to use this tool
- Select or drag in the PDF files you want to combine.
- Drag the file cards into the order you want. The top card becomes page one.
- Press Merge PDF, then download the single combined file.
When this is the right tool
- A signed contract. You have the original PDF and a scanned, signed signature page. Merge puts them back into one document.
- An application or tender. Cover letter, CV, certificates and ID — eight separate PDFs that have to arrive as one.
- A month of invoices going to your accountant as a single file instead of thirty attachments.
- Chapters or sections written separately and assembled at the end.
- Scanned pages that your scanner saved one page per file.
Before you merge
- Password-protected files cannot be read until they are opened. Run them through Unlock PDF first, with the password you are entitled to use, then merge.
- Images are not PDFs. JPGs and PNGs need converting first with JPG to PDF.
- Check the order on screen before pressing the button. It is faster than fixing it afterwards.
How it works
Merge, or one of the other tools?
Three tools here sound similar and do different jobs:
- Merge PDF — joins whole files together. Use it when you have several documents and want one.
- Organize PDF — works inside one file: reorder, rotate and delete pages. Use it when the pages are already in one document but in the wrong order.
- Split PDF — the opposite of merge. Breaks one file into several.
A common sequence: merge everything first, then open the result in Organize PDF to fix any page that came out upside down.
How many files, and how big
There is no quota here, because there is no server to impose one. The real limit is your own device's memory: the whole job happens in your browser's working memory, so a laptop with plenty of RAM will handle far more than a five-year-old phone.
In practice, ordinary documents — contracts, invoices, reports — merge in large numbers without trouble. Where you may feel it is with scan-heavy files of several hundred megabytes each. If a very large merge struggles, do it in two goes: merge the first half, merge the second half, then merge those two results.