Drawing from niche theory and the uses and gratifications approach, this study explores the gratification niches of TikTok as a new social media app. As a first step, we developed a catalogue of motives for using TikTok to assess users' gratifications. As a second step, we explored the predictive value of these motives for TikTok's competitive displacement potential among its users during the day and night and actively posting content. In a sample of N = 1051 TikTok users in China, parallel analysis revealed four distinct gratifications for TikTok use: socially rewarding self-presentation, trendiness, escapist addiction, and novelty. Age−gender stratified analyses showed that novelty was the most relevant motives for using TikTok across all users. Age was positively correlated with trendiness and negatively correlated with escapist addiction. We could only observe one gender difference for addictive escapism being more relevant for women. Finally, TikTok's potential for competitive displacement of other social media apps seemed to be “time-of-day-specific” with trendiness driving daytime use, novelty driving nighttime use, and posting TikTok videos being driven by socially rewarding self-presentations. Our findings therefore come with implications for theorizing on comparative social media uses and gratifications.