PDF Optimizer

Cleanup

compression Selects the compression action for the file.
compress-entire-file Compress document as a single unit
compress-document-structure Compress the document structure only
remove-compression Removes compression from file streams

Optional. Enable any of these values by adding it to the profile and setting it equal to ON.

flate-encode-uncompressed-streams Compress uncompressed streams using flate.
convert-lzw-to-flate Recompress LZW-compressed streams using flate.
optimize-page-content Removes redundant content streams, or page text.
optimize-for-fast-web-view Place all the information needed to render the first page of the document near the beginning of the file.

Flate, or Deflate compression, is an open source standard widely used for creating zip files and with PDF. It is commonly used for PNG image files, and is much more widely used than lzw.

Lzw, Lempel-Ziv-Welch, is a universal data compression algorithm, once widely used with Unix platforms. This method appears in some old PDF documents but it is rarely used any longer.