The Google ranking algorithm is constantly changing. Multiple times a day, Google introduces small tweaks, but every now and then, they implement larger changes that more dramatically alter the SERPs. It can certainly be hard for SEO professionals to keep up with all these changes, so this post will give a brief overview of some of the most important changes to the Google ranking algorithm over the past few years. For a more in-depth look at these and some of the more minor algorithm updates, Moz provides the most up-to-date history of changes.


First things first, it’s important to understand how SEOs uncover these algorithm updates. Google doesn’t always announce when changes are coming, nor do they confirm when an update has occurred. SEOs across the globe come together to discuss changes in the SERPs on forums, social media, and news sites. Combining their knowledge and data, collectively SEOs are able to determine how volatile the rankings are at any given point in time. Highly volatile rankings (rankings that are showing significant changes) point towards some form of an update with Google’s ranking algorithm. Luckily, you don’t always have to keep up with all the industry chatter. Sources like SEMRush provide helpful tools that give you an idea of how volatile the SERPs are each day overall and for a variety of verticals in particular.