Americans are using the Internet more for video, both to post their own snippets and to view videos of others, a survey showed Thursday.

The Pew Internet Project survey found that the percentage of American adult Internet users who upload or post videos online has doubled in the past four years, from 14 percent in 2009 to 31 percent today.

And 78 percent said they watch or download videos, up from 69 percent four years earlier.

Younger Internet users are twice as likely to post and share videos online than their older counterparts. Pew found 41 percent of 18-29 year-old Internet users and 36 percent of those ages 30-49 post or share videos online, compared with 18 percent of those over 50.

"Online video consumption continues to be concentrated among the youngest online adults, and those with higher education and income levels, but over time it has grown substantially among virtually all groups of online adults," report author Kristen Purcell said in a statement.

As in 2009, comedy and educational videos are among the most widely viewed video genres, with more than half of online adults saying they watch those categories.

Music videos showed the largest growth in viewership between 2009 and 2013, from 32 percent to 50 percent.

Some 12 percent said they watched adult-themed videos -- 25 percent of male Internet users and eight percent of females.

Among those who post or share videos online, 35 percent said hoped or believed this would go "viral." Just five percent of those who have posted said they had regrets about at least one of the posted items.

The findings are from a representative telephone survey of 1,003 adults conducted from July 25 to July 28, with an estimated margin of error of 3.6 percentage points.