Every tool on this page runs entirely in your browser. Your PDFs are read on your own device, processed there, and only the result you download leaves the page. There is no account, no queue and no server copy — which is also why the tools stay free: serving a page costs almost nothing once the code is downloaded.
Two honest limits apply across the whole set. A single PDF over 50 MB is refused and one over 30 MB gets a warning, batches are capped at 20 files, and files past a combined 100 MB are skipped and named. Those limits protect your browser’s memory, not a server. And a few tools state their own limits plainly on their pages: compression re-renders pages as images, text extraction needs a real text layer, and the HTML tool prints through your browser.
Start with the job, not the tool name: combining files is Merge, taking pages out is Split or Extract Pages, making a file smaller is Compress, and turning a PDF into something else is PDF to Text, PDF to Images or PDF to Markdown. Every tool page explains its own options and limits before you download anything.