PDF tools

A PDF fixes a page in place: the same margins, fonts and line breaks wherever it is opened. That is its whole value, and also why editing one is harder than editing almost any other document — the file describes a finished page, not the text that produced it.

These tools work with the page structure rather than the text inside it. Joining, separating and reordering pages are all operations a PDF is genuinely good at, which is why they are quick and lossless. Rewriting the words in a paragraph is not, and no browser tool should claim otherwise.