Please forgive the cheesy, Game of Thrones reference but I thought it was a better option than the currently trending phrase #mobilegeddon

On April 21st 2015, Google will introduce a new ranking algorithm that will give preference to sites that are “mobile-friendly”. Changes in the complex methods by which Google ranks it’s search results are not uncommon but this latest update has made headlines as it’s the biggest change in 2 years and one that has the potential to have a big impact on organic search traffic.

The update was announced in February of this year on Google’s Webmaster Central Blog:

“Starting April 21, we will be expanding our use of mobile-friendliness as a ranking signal. This change will affect mobile searches in all languages worldwide and will have a significant impact in our search results. Consequently, users will find it easier to get relevant, high quality search results that are optimized for their devices.”

The use of the word “significant” above is…well, significant - previous major updates including Panda and Penguin simply labelled sites as being mobile friendly whereas the April 21st update will actually change the position of search results based on whether the sites are mobile friendly or responsive.

While visible results are not expected immediately, this will be a STARK warning (see what I did there!) to those website owners who have yet to make the leap to modern web standards such as responsive design.

The shift in web usage to mobile devices has been exponential over the last 3-4 years and arguably no single company knows more about the importance of mobile than Google. As the world’s most popular search engine and the creator of the most used mobile platform in Android, Google has also more to gain by ensuring that more sites are mobile compatible and capable of increasing the available advertising space for mobile ads.

Again it remains to be seen how quickly search engine results will be affected. April 21st is simply the date on which the new algorithm will come into effect across all languages and regional variation of Google’s search engine and other web properties. However over the coming weeks and months site owners will see their search engine listings start to slide either up or down depending on their “mobile friendliness”. For sites that rely heavily on search results for direct or indirect revenue this positive or negative impact will be “significant”.