How Do Vertical Video Algorithms Work on Social Media?
Vertical video (TikTok, Instagram Reels, and YouTube Shorts) has become the dominant medium for mobile entertainment. But how do algorithms choose which videos get millions of impressions and which ones stall? The primary ranking signal is Average View Duration and Completion Rate. If a viewer scrolls away within the first 3 seconds, the algorithm assumes the video is uninteresting. Using a compelling visual or spoken "hook" in the opening seconds is essential. The second factor is active engagement: likes, comments, shares, and saves. Shares and saves carry the highest weight because they signal that the content has long-term value to other users, triggering viral recommendation loops. Lastly, platforms index metadata to match videos with target audiences. Captions, tags, audio tracks, and auto-transcribed voiceovers help search bots understand the content context. Optimizing for these variables while maintaining a consistent upload schedule is the most reliable way to build a loyal audience on vertical platforms.