One of the world’s hottest apps right is about to get bigger.

Tik Tok -- the popular short video platform where teens in Asia post clips of themselves dancing to hit tunes and performing viral stunts -- is merging with its Western equivalent Musical.ly, according to their owner -- China’s Bytedance.

A source familiar with the matter tells the South China Morning Post that the move is part of a reorganization effort to “create better synergies,” taking advantage of the two apps’ many similarities.

The merger means Tik Tok’s users in Asia and Musical.ly’s users in the US and Europe can now see content created by each other -- but, notably, not users in China.

The Chinese version of Tik Tok, known as Douyin, will remain separate.

Tik Tok (left) and Musical.ly (right) offer similar tools for users to edit their video. (Picture: Tik Tok/Musical.ly)

Launched in 2016, Tik Tok beat YouTube in the first quarter this year to become the world’s most downloaded iOS app, according to US research firm Sensor Tower.

The viral app rolls popular elements from Snapchat, Dubsmash and the now-dead Vine into one single platform, allowing users to make 15-second clips by choosing from a library of funky background tracks and eye-catching visual effects.

Musical.ly, using a similar format, gives “Musers” (Translation: Musical.ly users -- Tik Tok fans are called “TikTokers”) their own shot at 15-second fame by creating video of themselves lip-syncing or singing in their own voices. Even stars like Ariana Grande and Demi Lovato have appeared on the platform.

Launched two years before Tik Tok, Musical.ly was made by Chinese entrepreneurs Louis Yang and Alex Zhu. They joined Bytedance after the Chinese online content giant bought their app in November.