Build an Engagement Decay Analyzer: How Fast Do Posts Die?

You post a TikTok. It gets 10K views in the first hour. You celebrate. 24 hours later: 12K views. 48 hours: 12.1K. It's dead. Meanwhile, your competitor posted at the same time. First hour: 8K views. Seems worse. But 48 hours later: 45K. A week later: 200K. Their content has legs. Yours doesn't. The difference isn't luck. It's engagement decay rate — and almost nobody tracks it. I built a tool that measures exactly how fast posts lose momentum and which content types have the longest shelf life. Here's the whole thing. The Stack Node.js – runtime SociaVault API – fetch post data over time Math – decay curve fitting Why Decay Rate Matters More Than Total Engagement Two posts, same creator, same niche: Metric Post A Post B Views at 1 hour 10,000 5,000 Views at 24 hours 12,000 20,000 Views at 7 days 13,000 80,000 Decay rate Fast (dies in hours) Slow (grows for days) Post B wins by 6x despite starting slower. If you only measured "first hour performance," you'd double down on Post A's styl