How To: Reduce the size of PDFs exported from ArcMap
Suggestions provided describe how to reduce the output file size of maps exported to PDF from ArcMap.
Remove transparency and picture marker symbology. Refer to the ESRI Knowledge Base article in the Related Information section below for a sample tool that detects if any of the layers in the map are symbolized with transparency and/or picture marker symbology.
Replace the Picture Fill symbols with simpler, vector fills.
Replace the Picture Marker symbols with font-based vector marker symbols.
Remove raster data sets.
Data and Layout
Reduce the display quality of all raster layers:
Right-click the raster layer in the Table of Contents and select Properties.
In the Layer Properties dialog box, select the Display tab.
Lower the display quality in the Display Quality slider from Normal.
Decrease the page size of the map.
Remove any unnecessary map elements and data frames not visible on the layout.