Google has announced that it will be splitting its search index into two separate versions, for mobile and desktop, in the next few months. The mobile index will update more regularly, with the desktop index updating more slowly and effectively becoming a secondary index. The news was announced by Gary Illyes, a Google Webmaster Trends Analyst, at the Pubcon tech conference. Google hopes that the announcement will encourage webmasters to optimise their websites for mobile. Google says that websites are classed as mobile-friendly if they avoid using Flash, use text that is large enough to read without zooming in, adjust content so that it fits neatly on the screen without horizontal scrolling, and spaces buttons and links far enough apart that they are easy to tap.