ASPX file are the Active server page extended files. There are many way to convert ASPX file to PDF but the easiest one is Before you convert the ASPX to PDF first you need to convert it into oxps file . Open the ASPX file using the browser like Google Chrome Firefox etc. Press the Ctrl+P together to open the print page. At the left side you will find the option Change click on Change button and select the option Save as PDF option. In the last press save button to save the ASPX to into PDF.