Shrink a Scanned PDF Under 500 KB: Keep the Important Page Sharper
If a scanned PDF fits an upload limit but the smallest numbers become hard to read, compress the easy-to-read pages more and keep the critical page sharper. The final PDF still needs to pass two checks: it fits the limit, and every required detail is legible. What changed under the same limit I re-encoded the same three synthetic scan pages locally, using grayscale JPEG images in a PDF. Both copies contain three pages in the original order. I treated 500 KB as 500,000 bytes and aimed to stay below it. Same settings on all pages: 120 DPI, JPEG quality 55, 476,724 bytes . Different settings by page: pages 1 and 2 at 72 DPI and quality 45; page 3 at 165 DPI and quality 65. 469,474 bytes . The same crop at the same scale. The page-specific copy preserves more detail on page 3 by allocating fewer pixels to pages 1 and 2. This comparison does not establish readability on the other pages. Try it with an offline PDF editor Keep the original. Mark pages containing faint stamps, fine prin...