Add as many files as you like, drag the cards left or right until the sequence is right, and download one PDF. Nothing is uploaded.
One card per file, numbered in output order. Drag a card to move its pages; the cover tells you which file it is.
Everything is drawn as vector and merged back into the original PDF, so it stays sharp at any zoom or print size, with labels that remain selectable, searchable text.
Add them all at once or a few at a time, and keep adding after you have started. The same file can be added twice without the two copies interfering.
Grab a card and move it left or right; a marker shows where it will land. The arrows in each card's corner do the same thing one step at a time, and the badge on every card is its position in the output.
Only the first page of each file is drawn, never every page. That is what keeps this tool cheap on a 300MB set, and it is enough to tell two similarly named scans apart while you arrange them.
Pages are copied across as they are. Text stays text, vectors stay vectors, images keep their own resolution. A searchable PDF comes out searchable.
Source files are opened one at a time while the output is built and released before the next is read, rather than all of them being held open at once. A 300MB merge measured about 2.4GB at its peak, and produced a correct file.
Every move is undoable, so trying an order costs nothing. Removing a whole file asks first, because that is the one step undo does not cover.
Most free online PDF tools upload your file to somebody's server. This one
cannot, even if it wanted to. The page ships with a Content-Security-Policy of
connect-src 'none', which means the browser itself refuses to let it
open a network connection.
Check it yourself: press F12, open the Network tab, and use the app all day. It stays empty. DevTools is left working and console errors are not suppressed, precisely so the claim stays testable.
This tool has one job, so it has few controls. Dragging is the main one.
Version 1.10.9 MBChrome or EdgeWindows, macOS, Linux
Launch without downloading DownloadWhole files only. To drop individual pages use Vuiso Split PDF, and to turn pages that came in sideways use Vuiso Rotate PDF. Interactive form fields and digital signatures do not survive being merged into a new document, which is a limit of merging PDFs in general - if a signature matters, merge before signing.