How it works
Add two or more PDFs. Each one appears as a card showing its first page and page count. Put them in order by dragging the cards, using their arrow buttons, or with the keyboard: focus a card's handle, press Space to pick it up, move it with the arrow keys, and press Space again to drop it.
Press Merge and Vimorby copies every page, in order, into a new PDF using the open-source pdf-lib library, running in a background worker so the page stays responsive. Pages are copied as they are, so text stays selectable and nothing is re-compressed.
What gets kept
Page content, size, rotation, fonts and images are kept exactly. Links between pages, bookmarks and interactive form fields from the original files may not survive merging, so check the result if you rely on them.
PDFs protected with a password or encryption can't be merged. Vimorby tells you which file is locked so you can remove the protection first.
Your files are processed by your own browser, inside this tab. Nothing is uploaded, so there is no server copy to delete, and the page keeps working if you go offline after it loads.