The forecast: This year, TikTok users in the UK will grow by 12.6% for a total of 17.5 million. TikTok, which overtook Twitter users last year, will surpass Snapchat users by year-end and continue its upward climb.

Dive deeper:

• TikTok's user growth has been nothing short of spectacular, both in the UK and globally. It will enjoy double-digit growth this year among users under 18 and above 35, growing the fastest in older users.
• Use of the ByteDance-owned app is already highly saturated among young adult users in the UK. Of the 17.5 million TikTok users this year, 7.6 million are Gen Z and 5.7 million are millennials.
• Snapchat will remain ahead of TikTok among UK users ages 18 to 34 this year, meaning TikTok's uptick among older and younger users is what will really propel it ahead of its competitor.
• Less than 30% of UK internet users overall currently use Snapchat, and while it's still seeing growth, TikTok's growth trends far steeper. The video-sharing app beat Snapchat this year and will top 30% of internet users next year.
• Meanwhile, TikTok's UK ad revenues are already ahead of Snapchat and will nearly triple this year. Snapchat will hit $385.1 million in ad revenues, while TikTok's will surpass $1 billion.

Looking ahead: TikTok is not done growing yet. By 2025, the app will pass 20 million users. But among Gen Z, use will remain behind Snapchat, as well as Instagram, throughout our forecast.