PDF Tools
Compress PDF to 500 KB
Compress a PDF to under 500 KB - comfortable for longer documents, retaining near-original quality while meeting typical portal limits.
The algorithm
500 KB is a loose target that preserves most of your PDF's visual fidelity. The tool typically completes in 2-3 compression attempts and produces output that's visually indistinguishable from the source for most eyes.
Suitable for scanned reports, multi-page contracts, academic transcripts, and any document where you want to shrink the file for email or portal upload without noticeably degrading it.
A real use case
Common use: Email attachments (many corporate email servers cap individual attachments at 1-2 MB combined; getting a report to 500 KB leaves room for other files). Also suitable for university application portals that cap PDF uploads at 500 KB-1 MB.
Common questions
Is the quality better than 100 KB or 200 KB?
Yes - more headroom means higher JPEG quality per page. For a typical scanned document, the 500 KB output is close to the original visually.
Why not just use the regular PDF compressor?
The dedicated 500 KB target guarantees the result is under 500 KB. The generic compressor shrinks files but doesn't aim at a specific size.
Is this really private?
Yes. The whole compression runs in your browser using JavaScript and Canvas APIs. Your PDF is never uploaded, stored, or seen by us. You can disconnect from the internet after the page loads and it will still work.
Will the text still be selectable in the compressed PDF?
For aggressive KB targets, each page is rasterized into a JPEG and embedded as an image, which makes text non-selectable. If you need searchable text, pick a larger target or use the regular compressor at /tools/pdf-compressor/.
What file size can I compress?
Up to around 200 MB on most devices. Very large or very long PDFs may exceed browser memory limits - if that happens, try splitting the PDF into smaller sections first.
Why does my file end up slightly under the target rather than exactly at it?
The tool uses a binary search to find the highest JPEG quality that still fits under the target. It stops at the first setting that lands under the limit, so output is always a little below the ceiling - which is exactly what upload portals want.