Last updated 23 August 2026
What merging does and doesn't do
Every page from every file is copied into a new PDF in the order the files are listed, keeping text as text and images at their original resolution — nothing is re-rendered, flattened or recompressed in the process.
It can't merge a PDF that's password-protected without first removing that protection, since the file needs to be readable to copy its pages. Unlock it first if that applies to one of your files.
What survives the merge, and what does not
Pages, text and images carry over exactly as they were — nothing is re-rendered, so quality and file size behave predictably and text stays selectable and searchable.
Some document-level features do not survive, because they belong to the original file rather than to any page. Bookmarks and outlines, form fields and their saved values, digital signatures, and attachments are the usual casualties. A signature is the important one: merging changes the document, so any signature that certified the original is no longer valid, by design.
Order is set by the order you add the files, so it is worth arranging them before you merge rather than fixing it afterwards. Encrypted files are the other thing to check first — a PDF that asks for a password to open has to be unlocked before it can be combined with anything.
Related guide: Preparing artwork for print without a reprint
Common questions
Does merging change the quality of my PDFs?
No. Pages are copied exactly as they are — text stays text, images stay at their original resolution. Nothing is re-rendered or re-compressed.
Can I merge password-protected PDFs?
Not directly — an encrypted PDF needs to be unlocked first. Use the Unlock PDF tool if you know the password, then merge the unlocked file.
Is there a limit to how many PDFs I can merge?
No fixed limit — it depends on your device's memory, since the merge happens entirely in your browser rather than on a server.