The most common reason a PDF balloons in size isn't the text — it's embedded images saved at unnecessarily high resolution, especially from scanned documents or presentations exported with full-quality screenshots.
Effective PDF compression re-encodes the document's internal structure and, where applicable, downsamples embedded images to a more reasonable resolution for on-screen or email use — without touching the actual text content, which stays sharp at any zoom level.
A PDF that's already mostly text with minimal images is close to its minimum size already; re-compressing it won't meaningfully shrink it further, and that's a legitimate, honest result rather than a tool failing to work.
Typically 60–90% depending on the original content, especially for image-heavy PDFs.
No, text remains crisp — compression primarily optimizes embedded images.
Free users can compress files up to 100MB; Pro users up to 500MB.