Merge PDF
Join two or more PDFs into one document. They go together in the order shown above the button, and you can shuffle them around before anything happens.
Runs entirely in your browser. Your files are never uploaded.
How to use Merge PDF
- 1Pick the PDFs you want to join, or drag them onto the box above.
- 2Use the arrows to get them into the right order.
- 3Press Merge PDFs and download the file.
What happens to your pages
Pages get copied from each file into a new one. Nothing is re-encoded on the way through, so text stays selectable and searchable, images keep whatever quality they had, and every page keeps its own size. Put a scanned A4 contract and a US Letter invoice in the same merge and you get a document with both sizes in it, which is what you wanted. Nobody opens a merge tool hoping their invoice gets stretched.
Because it's a copy rather than a re-render, big documents go through quickly. A 300-page file merges about as fast as a 3-page one.
Order is whatever the list says
The output follows the list above the button, top to bottom. Worth checking, because dropping ten files at once almost never gives you the order you expect. Browsers hand files over in whatever sequence the operating system felt like, which on Windows often means chapter-10 lands before chapter-2.
The arrows beside each file move it up or down. Fix the order there rather than merging, looking at the result and starting again.
Things that won't make it across
Page content comes over: fonts, vector graphics, images, page dimensions. Links that point at another page inside the same document usually keep working, since the page they point at got copied too.
What doesn't survive is anything that belongs to the document rather than to a page. Bookmarks, the table of contents, form fields, attachments and document metadata all live at that level, so they're gone from the merged file. Digital signatures are gone as well, and they have to be. A signature certifies one exact set of bytes. Merging changes the bytes, so a signature that survived would be lying.
When a file won't open
Password-protected PDFs get refused, with a message saying so. Some tools will happily open an encrypted file, ignore the encryption and hand you garbled output, which is worse than being told no. Remove the password in whatever application put it there, then come back.
The other common failure is a file that didn't finish downloading. It looks fine in a folder listing but stops partway through, and you'll get an unreadable-file message. Download it again.
Limits
- 100 MB per file. Past that you're limited by your own device's memory, not by a server.
- Password-protected PDFs need unlocking first.
- Bookmarks, form fields and signatures don't carry into the merged file.
Frequently asked questions
- Do my files get uploaded anywhere?
- No. The merge runs in your browser, using your device's memory and processor. Nothing is sent to us, which is why there's no queue, no account and no waiting around.
- How many PDFs can I combine at once?
- There's no set limit. What stops you is memory, since every document has to be held open while its pages are copied. On a phone, a few dozen normal documents is realistic. On a laptop, considerably more.
- Will the merged file be smaller than the originals added up?
- A bit smaller, because things like fonts get stored once instead of once per file. Don't expect much. If you need a real reduction, use the Compress PDF tool afterwards.
- Can I merge a PDF that has a password on it?
- Not directly. Open it in the application that added the password, save a copy without one, and merge that instead.