What makes PDFs large?

PDFs can grow because of embedded images, embedded fonts, high-resolution scans, and unnecessary objects. Compression tools target these areas differently.

Compression strategies

Images — Downsample or recompress images inside the page content when the tool supports it.
Structure — Remove redundant objects and duplicate streams where safe.
Linearization — Some workflows optimize for web viewing; not always the same as “smallest file.”

Using PDFZen

Start with the Compress PDF tool. Compare the output size to your original and open both in a viewer to confirm text remains crisp for your use case (print vs screen).

Trade-offs

Aggressive compression can affect photos and gradients more than plain text. For legal or archival documents, prefer conservative settings and keep an original copy.