It's a paid tool, after all, but there was one free tool that performed better with default settings. Using default setting, our sample file shrunk from 11,775KB to only 212KB, making Adobe Acrobat Pro one of the most effective PDF compressor in this list. To help with this, in the Advanced Optimization window, click Audit Space Usage, and you'll be able to see how much space each kind of element is taking up within the file.
If you click Advanced Optimization, you'll have more options to ensure you maintain the quality you need. Once you click Save, Acrobat will apply default settings to your file to attempt to reduce its size. Next, you'll choose the file location and name. If you click Reduce File Size, you can choose to reduce a single or multiple files. A toolbar with a few options will appear just above the PDF. To get to this, open your PDF in Acrobat, click Tools > Optimize PDF. This is one of the best and easiest ways to shrink a PDF document. If you have Adobe Acrobat installed on your computer, there's a tool within the application called “PDF Optimizer”.
