PDF is the format people reach for when something has to look the same everywhere — a contract, a boarding pass, a scanned form. It's also the format that's hardest to edit once you have it, which is why these nine tools exist.
Organising pages
Merge combines several PDFs into one file in the order you choose. Split pulls out single pages or ranges as a downloaded zip. Rotate fixes sideways scans, a page at a time or all at once with a preview before you download. All three run entirely in your browser using the pdf-lib library, self-hosted rather than loaded from a CDN.
Creating a PDF
Image to PDF bundles photos or scans into a single file — handy straight from a phone camera. DOC, Excel and PowerPoint to PDF freeze a document's layout so it can't reflow on someone else's machine; these three need real conversion software (LibreOffice, running server-side) that a browser doesn't have, so uploads are capped at 10 MB.
Optimising and inspecting
Compress PDF re-encodes images and strips unused objects to shrink a file for an email attachment limit, using Ghostscript on the server — text stays selectable, it isn't a rasterized copy. PDF Metadata reads title, author, producer and creation date from a file locally, without changing anything.
Why some tools have a size limit and others don't
The five browser-based tools have no server to overload, so the only ceiling is your own device's memory. The four server-based ones run real software on a shared machine, so uploads are capped at 10 MB to keep it responsive for everyone else using the site at the same time.