The messaging app Snapchat has left Twitter behind to become the third most used social media app among the millennial group - 18 to 34 year olds.
Almost a third of the 18 to 24-year-olds now use Snapchat, compared to 23.8 % of Twitter app users, said the latest Mobile Metrix report by US internet analytics company comScore.
Facebook is still the most popular social media app with 75.6 % people using it, followed by Instagram with 43.1 % users.
At 32.9 %, Snapchat's popularity has more than doubled from 12 % in November last year.
Vine is used by 10.7 % of millennials while Pinterest has 17.9 % users.
At the bottom is Tumblr with 6.3 % users.
Snapchat's popularity is also growing among 25 to 34-year-olds and in the over-35 age group - albeit more slowly than among the younger age group, the report said.
Last year, its co-founder Evan Spiegel turned down a $3 billion acquisition bid from Facebook.
Facebook then launched a rival app called Slingshot.
Instagram, which is owned by Facebook, followed this with the launch of Bolt.