It's regional and context-specific. On the U.S. coasts, "guys" is considered gender-neutral when used in an address (e.g. "you guys" or "guys, listen to this").

It's regional and context-specific. On the U.S. coasts, "guys" is considered gender-neutral when used in an address (e.g. "you guys" or "guys, listen to this"). It seems like depending on region it might be the case that "guys" can be broader (e.g. "Facebook guys" being gender-neutral), although personally as someone who grew up in the Northeast that sounds non-idiomatic to me. (Edit: here's a link to the Harvard Dialect Survey that shows regional variations in addressing groups of two or more people: http://www4.uwm.edu/FLL/linguistics/dialect/staticmaps/q_50.html http://www4.uwm.edu/FLL/linguistics/dialect/staticmaps/q_50....) There's been some linguistic research that shows that men are more likely to interpret "guys" as neutral than women, although unfortunately I don't have a link. Some people prefer not to use the "guys"-as-gender-neutral slang even on the coasts both because it sets male as default and because it can be misinterpreted by people from other parts of the U.S. and the world. Personally I've stopped using it unless I'm actually addressing a group of dudes.