The Web Robots Pages. Web Robots (also known as Web Wanderers, Crawlers, or Spiders), are programs that traverse the Web automatically. Search engines such as Google use them to index the web content, spammers use them to scan for email addresses, and they have many other uses. On this site you can learn more about web robots. Includes The /robots.txt checker that can check your site's /robots.txt file and meta tags.