Google uses a variety of algorithms and factors to determine the ranking hierarchy of websites in keyword search results. The specific algorithms and their inner workings are proprietary and not fully disclosed by Google. However, based on information Google has released and industry analysis, here are some of the key algorithms and factors involved:
PageRank: This is one of the oldest and most well-known algorithms used by Google, developed by its founders Larry Page and Sergey Brin. PageRank evaluates the quality and quantity of links to a webpage to determine a rough estimate of the website’s importance. The underlying assumption is that more important websites are likely to receive more links from other websites.
Panda: Introduced in 2011, the Panda algorithm focuses on content quality. It aims to lower the rank of “low-quality” sites or “thin” sites and raise the rank of higher-quality sites. Quality is assessed by several metrics which could include site speed, user engagement, content originality, and the thoroughness of the content.
Penguin: Launched in 2012, the Penguin algorithm deals with the quality of links. It targets sites that have obtained many of their backlinks through spammy or manipulative techniques (such as purchasing links or obtaining them through link networks designed primarily to boost Google rankings).
Hummingbird: Introduced in 2013, Hummingbird is focused on parsing the user’s intent when making a search query, rather than just the individual keywords within the query. This allows Google to better understand the context and meaning behind queries, which helps in returning more relevant results.
Mobile-First Indexing: As more users access the internet via mobile devices, Google places an emphasis on mobile-friendly websites. This indexing primarily uses the mobile version of a website’s content for ranking and indexing purposes.
RankBrain: Launched in 2015, RankBrain is part of Google’s core algorithm and uses machine learning to determine the most relevant results to search engine queries. It is particularly useful for handling never-before-seen search queries.
BERT (Bidirectional Encoder Representations from Transformers): Rolled out in 2019, BERT allows Google to understand how combinations of words express different meanings and intents. This technology enables Google to get a better understanding of the context of words in search queries.
In addition to these algorithms, Google considers many other factors like site usability, the security of a website (HTTPS), page loading speed, and whether the content fulfills the user intent. Google continuously updates and adjusts its algorithms to better match users with the most relevant and quality content.