Towards mobile visual search, compact visual descriptors have been well advocated in both academic and industry endeavors. Moving Picture Experts Group (MPEG) initiated the remarkable Compact Descriptors for Visual Search (CDVS) standard activity in Jan. 2010 to push forward the frontiers of compact descriptors in mobile internet industry. In Oct. 2014, MPEG CDVS successfully entered the Final Draft of International Standard. CDVS made a series of significant breakthroughs in high performance and low complexity compact descriptors. In this paper, we give an overview of the MPEG CDVS standard, with emphasis on the development of the core techniques and their technical merits.