This year TikTok said it would host videos that were up to 10 minutes long. The Chinese-owned platform previously only allowed videos that were three minutes in length or shorter. Video-sharing platform TikTok has started testing a new landscape mode with select users around the world. Viral videos filmed in portrait mode have helped make TikTok the world’s fastest-growing social media app. TikTok is the most popular app among young people globally, and has been downloaded almost four billion times. Will this help Tiktok to compete with YouTube ?