Client-Side PDF Optimization
Most free online PDF compressors work by making you upload your sensitive legal or financial documents to their servers. We built a completely local, client-side optimizer that shrinks PDF file geometry directly in your browser's memory using `pdf - lib`.
How does it shrink the file?
When you compress a PDF using our tool, it performs several strict optimization passes over the internal data structures of the PDF format:
- Stream Compression: It repackages all raw data streams into optimized cross-reference tables (Object Streams) introduced in PDF v1.5.
- Metadata Stripping: Unused XML metadata overhead and bloated document properties are wiped clean to save bytes and protect privacy.
- Garbage Collection: Orphaned nodes resulting from multiple saves and edits over the years are eliminated.
Why did my PDF not shrink much?
If your PDF consists entirely of high-resolution scanned images or photographs, structural optimization will only save a few kilobytes. Drastic size reduction of image-heavy PDFs requires irreversible downsampling (e.g., blurring images from 300 DPI to 72 DPI), which requires a heavier ghostscript backend server and alters the visual fidelity.