Look at images and fonts
A photograph-heavy brochure may store many high-resolution images, while a ten-page text letter may reuse a small set of fonts. Embedded fonts improve portability but also take space. Reused resources may be shared across pages, so splitting a file can duplicate resources and increase the total size.
Understand local memory limits
This site accepts files of up to 50 MB each. A compressed file can expand greatly when rendered. A 3000 by 4000 pixel canvas needs about 48 MB just for four-channel pixel data, before the renderer, PDF objects and output are included.
Choose an appropriate workflow
Process large scans in smaller page groups. Export only the pages needed by the recipient. Check actual output bytes rather than assuming that a smaller page count always means a smaller file. The available structural compressor cannot promise a particular upload-portal limit.
Try the related tools
Further reading
Updated 2026-10-18. These are implementation notes and practical explanations, not a conformance certificate.