title_body: PDF Compressor online / software I have a very large Ebooks I would like to Compressor their sizes and maintaining the highest possible quality.
  
  Is there Best PDF Compressor software or online website that I can Upload my private Ebooks.
  
  Note: I'm looking for a safe website that can't share my ebooks.
upvoted_answer: I'm not sure what you mean by best. Best is subjective and dependent on various factors such as type of PDF document and acceptability of quality loss.
  
  However, Adobe Acrobat Pro DC offers an option to Reduce File Size.
  
  
  
  Similar software also offer such an option. Example: ABBYY FineReader (p. 3 of Source).