Compress PDF to 500KB — Keeps Text, Free & Private

500 KB is the usual cap for longer documents: reports, project files, multi-page certificates. At this size most office documents fit with no visible change at all. In our tests, a 30-page government report with photos went from 4.5 MB to under 1 MB with its text intact. Trimming the fonts alone took it to 1.3 MB, and recompressing only its pictures did the rest. Getting that same report under 500 KB, though, meant turning its pages into images.

Scans of up to a few pages fit comfortably at 500 KB. For long scans, the tool spreads the size across all pages and lowers the resolution evenly.

The honest limits. PDFs with a password or with security restrictions are left alone, because compressing them would save them without that protection. A digitally signed PDF can be compressed, but any change to the file makes the signature show as invalid; the tool warns you, and if the signature matters, upload the original. In fillable forms the fonts are kept whole, because whatever someone types later needs every letter. When the target is smaller than the text and fonts alone, the pages do become images. The result then says "pages as images", and the text, links, bookmarks and form fields are not kept; at very small sizes, check that small text is still readable. Pictures in print colours (CMYK) and black-and-white fax-style scans are not recompressed yet, so PDFs made of them reach small targets only as page images. Long documents take longer: a 141-page manual took between 10 and 45 seconds on a laptop. Everything runs in your browser, so the PDF is never uploaded.