Adobe Acrobat DC - Make your job easier with Adobe Acrobat DC, the trusted PDF creator. Use Acrobat to convert, edit and sign PDF files at your desk or on the go.
VisiPics - VisiPics does more than just look for identical files, it goes beyond checksums to look for similar...
Sumatra PDF - Sumatra PDF is a slim PDF/DjVu/EPUB/XPS/CHM/CBR/CBZ/MOBI viewer for Windows.
dupeGuru - dupeGuru is a tool for finding duplicate files on your computer.
Wondershare PDFelement - All-in-one PDF editor
Pixiple - Find images similar in pixel and/or metadata content