On-Page , Off-Page , Latest Protocols, Google Algoriths Search engine crawlers may look at a number of different factors when crawling a site. Not every page is indexed by the search engines. The distance of pages from the root directory of a site may also be a factor in whether or not pages get crawled.[45] Today, most people are searching on Google using a mobile device.[46] In November 2016, Google announced a major change to the way crawling websites and started to make their index mobile-first, which means the mobile version of a given website becomes the starting point for what Google includes in their index.[47] In May 2019, Google updated the rendering engine of their crawler to be the latest version of Chromium (74 at the time of the announcement). Google indicated that they would regularly update the Chromium rendering engine to the latest version.[48] In December 2019, Google began updating the User-Agent string of their crawler to reflect the latest Chrome version used by their rendering service. Traffic