Merge, split, compress and convert, entirely in the browser.
The shortest shelf on the site, and there is an honest reason for that. A PDF is a container that most browsers can display and very few can rewrite, so every one of these had to be built rather than wrapped around somebody else’s service. Each one runs in the tab. Your file is opened by the page you are looking at and never uploaded, which for a contract, a passport scan or a bank statement is the entire argument for using it here.
Restructure, shrink, or build one
Merge and split restructure. Merge concatenates several PDFs in the order you set; split pulls out one page, a range, or every page as its own file. Neither re-encodes anything, so text stays selectable and quality is untouched. Compress does rewrite — it re-encodes the images inside the document, which is where nearly all the weight of a scanned PDF actually sits, and it reports the before and after so you can decide whether the trade was worth making.
JPG to PDF and PNG to PDF go the other way, turning photographs or screenshots into one document with a page each. That is usually what a form demanding a single-file upload is after. What is not here needs a server or a language model to do honestly — turning a PDF back into an editable Word file, or reading text off a scan — and a tool that did either of those badly would be worse than not having one at all.