Below is a tutorial on how to compress PDF documents for free, using all free software, no shareware or free trial versions. Works on Windows Vista, Windows 7, and Windows 8.
My compression ratio (when set to medium quality) dropped 86% in one instance. 87MB down to 12MB. This is especially useful when people are needing to use PDFs in email links or you are distributing content via mobile.
We are going to download three pieces of software, they are all free and under 10MB. Please install in order given below with standard defaults set.
- IrfanView (File Viewer)
- IrfanView Plugins – http://www.brothersoft.com/download-irfanview-all-plugins-164981.html
- Ghostscript – http://sourceforge.net/projects/ghostscript/files/latest/download
We need to update one of the plugins that wasn’t included in that bundle above. This is the newest IMPDF.DLL plugin – http://www.comsquare.ch/files/downloads/ImPDF_0_90.zip
You will want to unzip the above file and overwite the one that is here:
C:\Program Files (x86)\IrfanView\Plugins
Now it’s time to launch Irfanview. When you do, right click on it and select “Run as administrator.”
Open the PDF that you want to compress and go to File > Save As.
Select PDF as the file type.
In the little floating box to the right, select “not needed (select settings now).”
Click on the “Compression” tab and in my example I am using medium settings.
Click on the “Security” tab and uncheck the “Activate Security” option, otherwise you will get an error about it being password protected.
Then on the original save window click “save.” The PDF conversion will take anywhere from 2 minutes to 15 minutes based upon the size of your PDF. It might appear to freeze, but it is working. You can always refresh (F5) where your saved file is being written to, just to double check that the file is growing and actively being created.