Pitt's big win is in the activism category for his Make It Right foundation, which he launched in 2007 to help rebuild New Orleans after Hurricane Katrina. Carrey garnered both a Webby and a people's voice award for his visually stunning official fan site that boldly showcases his unique creativity and trippy humor.
Recognizing achievements in more than 70 categories, including Web sites, online videos and films, blogs and other segments of digital culture, the 14th annual Webbys are considered the Oscars of the online world.
While academy judges like Martha Stewart and David Bowie decide the winners in the Webby categories, people around the world also have a say in the voting.
Other honorees include movie critic Roger Ebert for his wildly popular blog, Roger Ebert's Journal, Comedy Central host Stephen Colbert for Colbert Nation and actress Isabella Rosselini for her quirky short-film series, Green Porno, about animal attraction.
A complete list of winners is online.