New Technique Spots Scraper Bots by How They Scroll
A recent write-up explores a clever anti-bot detection method: analyzing scroll behavior to spot scrapers pretending to be human visitors. Many scraping bots, even ones built on headless browsers like Puppeteer or Playwright, don't scroll pages the way real users do. They either skip scrolling entirely, jump straight to the bottom, or scroll in perfectly linear, robotic patterns that lack the pauses, speed changes, and randomness typical of human interaction.
By logging scroll events, timing, and acceleration patterns, site owners can build a behavioral fingerprint distinguishing bots from people, without relying solely on traditional methods like CAPTCHAs, IP blocking, or User-Agent sniffing. The idea generated active discussion on Hacker News, with commenters debating how easily bot developers could adapt by simulating scroll noise, and whether such techniques risk misclassifying real users with accessibility tools or unusual browsing habits.