The 2016 contenders for the White House have used social media platforms such as Twitter and Facebook as campaign tools to an extent not seen previously in U.S. presidential politics.

But usage and tactics vary widely across the campaigns of the 11 top Republicans and three top Democrats in the race.

Following are some key social media usage and engagement statistics on the major candidates’ campaigns. Social media data were gathered on Republicans Donald Trump; Ben Carson; Marco Rubio; Ted Cruz; Jeb Bush; John Kasich; Chris Christie; Carly Fiorina; Rand Paul; Mike Huckabee; and Rick Santorum; and on Democrats Hillary Clinton; Bernie Sanders; and Martin O’Malley.