How to Detect Bot Traffic by IP Address (JavaScript)

If you run a website or API, bot traffic is a fact of life. Scrapers, credential stuffers, vulnerability scanners — they all hit your endpoints and skew your analytics. The good news: most bots are easy to detect with a few IP-based heuristics. In this tutorial, we'll build a bot detection middleware in Node.js that analyzes incoming requests using IP geolocation, ASN data, and behavioral patterns — all powered by free APIs. What Makes Bot Traffic Different? Bots leave fingerprints that humans don't: Datacenter IPs — Real users browse from ISPs like Comcast or Vodafone, not AWS or DigitalOcean High request rates — 100 requests per minute from one IP is not human behavior Missing headers — Bots often skip Accept-Language , Referer , or send suspicious user agents Geographic anomalies — Traffic from countries where you have no users The Detection Script Here's a complete bot detection system in ~60 lines: const http = require ( ' http ' ); // In-memory rate tracker const requestCounts =