PDF Compression

Microsoft Print to PDF does not generate the smallest PDF files by default. However, you can downgrade the image resolution settings to reduce the file size. For instance, if you reduce the image resolution from 600 x 600 dpi to 300 x 300, chances are that the size of your PDF file is reduced.

If you do not feel like to reduce the file size of PDF file while keeping the same image resolution in your PDF file, you would need other software tool to help you, such as PDF Compress software.