Video app TikTok this year is on track to surpass Instagram in the U.S. among Gen Z users, according to a May social user forecast by digital market research company eMarketer.

By the end of the year, eMarketer predicts that TikTok will count 37.3 million Gen Z users (or those born between 1997 and 2012) living in the U.S. who access the platform at least once a month. During the same period, photo-sharing site Instagram is expected to have four million fewer U.S.-based Gen Z users, or 33.3 million.

Gen Z mobile social users by platform, 2019-2025Gen Z mobile social users by platform, 2019-2025.

TikTok has exploded in popularity in the U.S. in the last year, with eMarketer noting that the China-based short-form video platform gained 11 million Gen Z users between 2019 and 2020 alone.

Messaging app Snapchat still boasts the largest user base for the nine-to-24-year-old demo (counting 42 million Gen Z users in the U.S. this year, according to eMarketer). However, that platform’s growth is also expected to taper off in the coming years, with TikTok anticipated to surpass Snapchat in terms of total U.S. users by 2023 (with 89.7 million users, compared to Snapchat’s 89.5 million).

TikTok is also expected to eventually narrow the gap with Snapchat among Gen Z users by 2025

In terms of total U.S.-based users, Instagram is still expected to remain the leading social network for the foreseeable future, counting 119 million users this year, compared to Snapchat’s 85.1 million and TikTok’s 66.5 million.