A Friendly Reminder to Make Sure Your Site Is Mobile-Friendly by Tomorrow Starting April 21, Google will incorporate a site's mobile-friendliness into its ranking algorithm.

Google is about to shake up the way its search algorithm ranks websites. Starting Tuesday, mobile-friendly websites – ones equipped with easily clickable links and text that resizes to fit the screen it's viewed on, among other features -- will rank higher than sites that aren't mobile-friendly when users search for something from a smartphone or tablet.

The changes in search ranking won't be subtle, either. In a blog post announcing the changes, Google promises that they will "have a significant impact in our search results."

Google announced this change back in February. The end result, Google says, is to make it easier for users "to get relevant, high quality search results that are optimized for their devices."

With more than 60 percent of search traffic pouring in from mobile, small businesses – especially ones dependent on local search – need to ensure they've made the necessary changes so that their sites aren't penalized by Google's new ranking system.

Google has provided companies with a guide to creating mobile-friendly websites as well as a test to see whether or not pages pass its mobile-friendly bar.

Related: April 21 Is Your Last Chance for Mobile Optimization Before 'Mobilegeddon'