The Drunk in Love hitmaker is up for Best Celebrity Site, while Williams' 24 Hours of Happy music video will go up against Bob Dylan's innovative Like a Rolling Stone site in the Best Use of Interactive Video category.
Comedy duo Ylvis are up for two awards, including Best Viral Video and Best Comedy: Individual or Short Form for their hit The Fox (What Does the Fox Say).
In the Best Comedy: Individual or Long Form category, Jerry Seinfeld's second season of web series Comedians in Cars Getting Coffee will go head to head with FunnyorDie.com's Between Two Ferns with Zach Galifianakis' Justin Bieber episode.
Additional nominees include U.S. talk show host Ellen DeGeneres for Overall Social Presence and action star Jean-Claude Van Damme for The Epic Split, a viral ad which features the actor performing a split in between two moving Volvo trucks, in the Best Branded Entertainment: Short Form category.
The winners of the 18th annual Webby Awards will be announced on 29 April (14).