Evince - Evince is a document viewer for multiple document formats: PDF, Postscript, djvu, tiff, dvi, XPS...
Online Convert - Convert files like images, video, documents, audio and more to other formats with this free and fast online converter.
Ghostscript - Documentation.
Convertio - File Conversion in the Cloud
ReaSoft PDF Printer - ReaSoft PDF Printer is a document creator and virtual printer installer for the Windows operating systems.
IMGCentury.com - This is free online image compressor you can use to compress image size. You can easily reduce multiple images sizes by using online image compressor tool.