In a Pew Internet & American Live Project survey, 31 percent of respondents said they posted videos, up from 14 percent in 2009.
The percentage of adults who watch or download videos has also grown over the past four years, from 69 percent of adult Internet users in 2009 to 78 percent today, the Pew report said.
Younger adult Internet users are posting or uploading the lion's share of online video, the Pew project found. Fully 41 percent of 18-29-year-old Internet users and 36 percent of 30-49-year-old users said they post or share videos online, compared with 18 percent of Internet users age 50 and older.
There's an economic component as well, the Pew survey found. Online adults living in higher income households (annual income of $75,000 or more) are particularly likely to post or share videos online when compared with those in households with annual incomes below $50,000.
Video-sharing sites like YouTube have been the main driving force in the increasing percentage of online adults who post, watch and download videos; the percent of online adults who use such sites has grown from 33 percent in 2006 to the current figure of 72 percent.
The figures come from a telephone survey of 1,003 U.S. adults conducted from July 25 to July 28, by land line and cell phone The margin of error was plus or minus 3.6 percentage points.