PDF tools that never see your documents: merging, splitting, rotating and compressing all happen inside your browser with a JavaScript PDF engine. For contracts, financial statements and IDs, that privacy property is the whole point: there is no server copy to worry about.
Start with the PDF Compressor for email-size scans, Merge PDF for application packets, and Split PDF when you need three pages out of a forty-page document.
Two of these tools work in fundamentally different ways, and picking the wrong one costs you something. Merging and splitting copy pages across untouched, so text stays selectable and quality is identical. Compressing re-renders each page as an image, which is what makes scans shrink so far, and which flattens form fields, signatures and selectable text in the process. So split first, compress last, and only compress when a size limit actually demands it.