Currently there are two optional ways to compress a PDF:
1) Online converter: If you’re using it but you failed, please try to compress again. Sometimes it could be network glitch. Please try again: https://online.foxitsoftware.com/
2) PDF Optimizer feature in Foxit PhantomPDF software: Foxit PhantomPDF is free to try out for 14 days. You may download it from Foxit website:
After the installation, you may go to File-> Reduce File Size.
Need a high volume, server based digital document conversion and compression solution? Try PDF Compressor!