What this compressor does
This tool reserializes a PDF using compressed PDF object streams. It is useful for PDFs with inefficient object structure, but it cannot promise a target size and it does not aggressively recompress every embedded image.
Important limitations
Encrypted PDFs are rejected. Modifying a signed PDF can invalidate its digital signature. Links, annotations, forms and bookmarks should be checked after optimization; preservation is not guaranteed for every complex PDF.