I Built an API That Detects 7,200+ Technologies on Any Website — Here's How the Detection Works

Every developer has wondered "what is that site built with?" I built an API to answer that question programmatically, and the detection system behind it is more interesting than you'd think. Here's how it works under the hood. The Problem Browser extensions like Wappalyzer can tell you what technologies a website uses. But if you want to check hundreds or thousands of sites programmatically — say, for market research, security audits, or competitive analysis — you need an API. BuiltWith offers one at $995/month. Wappalyzer's (now owned by Hostinger) starts at $450/month. I wanted something affordable, so I built my own. The result is DetectZeStack , a Go API that combines four different detection methods to identify technologies on any website. The Four Detection Layers A single HTTP request to a website gives you surprisingly little information. To get accurate results, you need to look at multiple signals. Layer 1: Wappalyzer Fingerprinting (~7,200 signatures) This is the heavy hitte