World Wide Web Consortium (W3C) permits web clients to check HTML and XHTML records for all around organized markup. Markup approval is a vital stride towards guaranteeing the specialized nature of pages. W3C approval is the way toward checking a sites code to figure out whether it takes after the organizing principles.
W3C Validation tools, validates Html or XHTML markup code with internation web standards. It helps you to determine possible errors in markup code that may cause confusion for search engine and results into slow or no search engine crawling.