Compress PDF to 500 KB

500 KB is a typical limit for uploads that hold a complete document rather than a single page: a signed contract, a multi-page application form, a coursework submission, a report attached to a support ticket or a document sent through a messaging app on a slow connection.

With 500 KB you have real room to work with:

• Typed reports and contracts with a few images almost always fit in Recommended mode, with no visible change to the text.
• Scanned documents of five to eight pages fit in color at about 100 dpi or in grayscale at 150 dpi, which is sharp enough for fine print.
• Brochures and slides exported to PDF with large photos fit if the photos are reduced to screen resolution, about 100 to 150 dpi.
• Scans of twenty pages or more need grayscale and a lower resolution, or splitting into two files.

For most PDFs at this size, Recommended is the right choice. It shrinks only the photos and scanned images inside the file and leaves text, vector graphics, links and form fields alone. The result looks identical on screen apart from the photos, and you can still search, copy and fill it in.

Choose Strong when Recommended can't get under 500 KB. That happens with PDFs whose size doesn't come from images: files with many embedded fonts, detailed technical drawings, maps or charts with thousands of points. Strong mode turns every page into a picture, which caps the size per page but removes selectable text. For scans this makes no difference, because a scanned page has no real text to begin with, and Strong mode adds the grayscale option.

The tool doesn't just apply one fixed setting. It first checks the strongest level to confirm that 500 KB is possible. Then it searches the levels between 50 dpi and 200 dpi, keeps the highest one that stays under the limit, and makes one extra attempt between the last two levels to use the remaining space. You get the best quality that fits, not just any file that fits.

If the original is already under 500 KB, it stays exactly as it is. If even the strongest level is too big, you get the smallest file the mode can produce, clearly marked, together with suggestions: grayscale, deleting unneeded pages or splitting the PDF.

In a typical oversized PDF the text takes up a few kilobytes per page and the photos take up the rest. A single photo straight from a phone camera can weigh 3 to 5 MB when it is pasted into a document, even if it is shown at the size of a postage stamp. The tool fixes exactly this: it recalculates each image to the resolution needed for the size at which it appears on the page, and re-saves it as an efficient JPEG.

That is why a 6 MB report with photos often ends up at 300 to 400 KB without any visible loss in the text. If you prepare the document yourself, you can help: insert photos at the size you need, avoid pasting screenshots of whole screens, and export to PDF with the standard quality setting rather than the press-quality setting.

An eight-page lease was printed, signed and scanned back in color with a phone scanner app. The PDF is 7.8 MB and the upload form accepts 500 KB. In Recommended mode with a 500 KB target, the tool settles at about 100 dpi and the result is 470 to 490 KB, with every signature clearly visible. If the scan shows a dark desk around the pages, crop it or rescan on a light surface first: an uneven dark background takes surprisingly much space, and removing it lets the same target keep a higher resolution.

Your PDF is processed locally in your browser; no part of it is uploaded. That makes it suitable for contracts, invoices, medical results and internal reports. There is no account and no watermark, and the original file on your disk is never modified. After the page has loaded, compression works even without an internet connection.