How to reduce PDF file size

Why PDFs get large

A PDF's size is almost never the text — text and vector graphics are tiny. The weight comes from embedded images: photos, logos and, above all, scanned pages, which are full-page pictures. A ten-page scanned contract can be many megabytes while a hundred-page text report is a fraction of that. Fonts, duplicated resources and uncompressed image data add the rest.

What actually reduces the size

• Re-compress the images. Lowering the quality of embedded images is the single biggest win, and it leaves text perfectly sharp. This is what our compress PDF tool does.
• Downscale oversized images. A photo embedded at 4000 px when the page shows it at 800 px is wasting space. Capping the maximum dimension shrinks the file further.
• Scan smarter. If you control the scan, use a sensible DPI (200-300 is plenty for text) and greyscale instead of colour where colour isn't needed.

How to hit a specific size (like 100 KB)

Many portals demand an exact ceiling. Rather than guessing quality settings, set the target directly: our tool searches for the highest quality whose output still fits. Jump to a common limit — 100 KB, 200 KB or 500 KB — and it aims there, telling you the exact size it reached.

When a PDF can't get small enough

A readable colour scan has a practical floor; forcing it to a tiny size turns it to mush. If you hit that wall, try greyscale, lower the maximum image dimension, split the document into parts, or share a link instead of an attachment. An honest "closest we could reach" result beats an unreadable file.

Keep text readable

Because only images are re-encoded, text and vector content stay crisp at every setting — so you can compress aggressively for upload limits without your certificates or forms becoming illegible.