Drop a PDF, get it back guaranteed at or under 500 KB — usually at high quality; recompressed locally with pages sharing one byte budget. Nothing is uploaded.
At 500 KB most everyday PDFs — a handful of scanned pages, a short signed form, a two-page letter with a letterhead — recompress with little visible loss: the fitter usually settles near the top of the quality range and simply rebuilds the file smaller. The mechanics are the same as every cap here: pages rendered locally by pdf.js, re-encoded as JPEGs that share one byte pool (a second pass redistributes whatever the simple pages didn’t use), reassembled into a PDF guaranteed at or under 500 KB — the downloaded file, not just the images inside it. Rwanda’s Irembo visa portal is a live example of the intent: passport bio page and application letter each as a PDF under 500 KB (verified spec).
A 20 MB scan-app PDF is usually 20 MB because the app embedded every page as a barely-compressed 3000-px photo. Re-rendering at document resolution (up to 2000 px on the long edge by default — the Max edge field moves that) is exactly the right fix, and the quality knob barely has to move. Photo-album PDFs are the opposite case: pictures eat bytes, and a big one may need real quality loss or a smaller render to make 500 KB — the per-page table tells you which pages paid for it.
The output holds pictures of your pages: no selectable text, no live links, no form fields, no digital signatures. Scans lose nothing real; text-born PDFs lose their text layer, so only push them through when the upload form cares about bytes. Page print-sizes are preserved exactly; password-protected files need the password removed first; nothing is uploaded anywhere. Several files (Irembo wants two separate PDFs) can be dropped together — each comes back under the cap on its own row, ZIP included — or merge them into one: tick Combine into one PDF and the dropped PDFs and images become pages of a single file under the cap. Tighter caps: 100 KB · 200 KB · 300 KB. Starting from photos: image to PDF under 500 KB.