Merge PDF
Merge PDF joins two or more PDF documents into a single file. Add as many files as you need, drag them into the order you want, and download one tidy PDF. Bookmarks from the source files are not preserved, but every page, its size and its rotation are carried over exactly.
1 Add your files
Enter the open password to use it here. It is checked in your browser and never sent anywhere.
2 Choose your options
How to merge PDF
Add your PDFs
Drag two or more files onto the box above, or click to browse. You can also paste a file with Ctrl+V. Each one gets a thumbnail so you can tell them apart.
Put them in order
Drag the files up and down, or use the arrow buttons. The list reads top to bottom — that is the order the pages come out in.
Merge and download
Press Merge PDF. The combined file is built here in your browser and offered as a download straight away.
What merging actually does to your pages
Merging does not re-render anything. Each page object is copied out of its source document and written into a new one in the order you chose, carrying its own fonts, images and dimensions with it. That is why a merged file looks identical to its sources and why an A4 report and a landscape slide can sit happily in the same document — every page keeps its own size and orientation.
What does not survive is anything that described the old documents as wholes. Each source had its own bookmark outline, its own metadata and possibly its own form definition; the new file has one of each, so those are rebuilt rather than concatenated.
A worked example
Twelve monthly invoices named invoice-1.pdf through
invoice-12.pdf are selected together. The file dialog hands them over in
alphabetical order, which puts invoice-10.pdf third — because "1" sorts
before "2" one character at a time. Drag invoice-2.pdf back up to second
place before merging, or rename the originals with leading zeros
(invoice-01.pdf) and the problem disappears permanently.
Limitations worth knowing
- Bookmarks from the source documents are not carried over, because the pages are copied into a fresh file. Links inside a page still work.
- Interactive form fields are flattened during the merge. Fill in the forms first if you need the values kept.
- A file with an open password cannot be merged until it is unlocked — the pages are encrypted and unreadable until then.
- Up to 60 files at 100 MB each. The real ceiling is your device's memory; if a large batch fails, merge it in halves and then merge the halves.
- Digital signatures on a source document are invalidated, since the signed byte sequence no longer exists in the new file.
Further reading
How to Merge PDF Files Without Uploading Them, Splitting, Extracting and Reordering
Related tools
Merge PDF — frequently asked questions
Up to 60 files in one pass, with a 100 MB ceiling per file. The real limit is your device's memory rather than a rule we impose — if the tab runs out of memory, merge in two batches and then merge the results.
No. Pages are copied across as they are, with their original resolution, fonts, images and page size intact. Nothing is re-rendered or re-compressed.
Internal links within a page are preserved, but the bookmark outline of each source document is not carried over, because the pages are copied into a fresh document. Form fields are also flattened away during the copy.
Yes. Each page keeps its own size and orientation, so an A4 report and a landscape slide can live in the same file. If you need them uniform, run the result through Crop PDF afterwards.
No. The merge happens in JavaScript inside this tab. Open your browser's network tab and watch — the only requests are for the page itself and the PDF library. Your documents stay on your device.
Only if you know the password. Enter it when prompted and the file is unlocked for this session. We cannot crack or bypass a password you do not have.