How the Google Algorithm Works: Google Search Explained

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Your ecommerce website is open for business, but how will customers find it? Aside from paid advertising and word of mouth, online visitors tend to discover businesses using search engines like Google. The higher you rank on search engine results pages (SERP), the more likely you are to gain new business.

Google processes billions of searches each month and ranks results using a complex algorithm based on hundreds of criteria. How exactly does this algorithm work? Here’s a peek behind the algorithmic curtain to better understand search queries, key ranking factors, and how to improve your site’s visibility. 

What is the Google algorithm

The Google Search algorithm is an ever-evolving system that retrieves content from its index (upward of 100 trillion web pages and counting) in response to a query. Google’s ranking algorithm makes informed predictions about which pages are most pertinent to the search query and arranges them in a list, placing the most relevant results at the top. Although it’s typical to talk about Google’s algorithm as a single thing, there are in fact many algorithms at work.

How does the Google algorithm choose search results?

The technology driving Google’s ranking systems is a secret, but Google has been forthcoming about some details, sharing that its algorithm considers five vital categories when ranking search results: meaning, relevance, quality, usability, and context. Here’s more on what these mean:


Google’s algorithm employs language models (AI systems trained on human language) to infer a search query’s intent. It fixes spelling and applies synonyms that correlate with similar content. 

The algorithm also gauges the user’s the preferred language and media types (like images or video) and considers locality to skew results in favor of nearby businesses. If the query contains trending keywords, Google’s algorithm up-ranks pages focused on current events and breaking news. 


When assessing an indexed site for relevance, Google’s algorithm essentially asks the question: Does the web page use words in the user’s search query? If query keywords match words on the page, it’s more likely relevant. 

The algorithm then goes further, taking aggregated, anonymized interaction data that’s been fed into machine-learning systems to predict other relevant content. Factors like page relevance, reliance on expert sources, and location proximity are weighted according to the algorithm’s interpretation of the query’s meaning and intent. 


Google’s algorithm prioritizes results that pass quality tests, defining quality as that which is most useful to the user. To determine quality, Google looks for indications of experience, expertise, authoritativeness, and trustworthiness—or EEAT. If a well-known expert writes an article for an authoritative established website, the page will likely have a high EEAT score. 


Whenever other reputable websites link to your web page, the algorithm concludes it’s more trustworthy and ranks your page higher. By creating unique, useful content, you increase your chances of building backlinks.


After content passes checks for meaning, relevance, and quality, the algorithm gauges usability. In other words, the web content should be easy to access, mobile-friendly, and fast-loading—delivering a positive user experience. 


Context includes geographical location, search history, and search preferences (such as default language and “Safe search on”). 

For example, a user from Philadelphia searching for “hockey” likely sees results relevant to the city’s professional hockey club, the Flyers. A search written in Spanish returns results in Spanish. Google’s algorithm considers recent search activity as part of the context too. 

Factors that affect how the Google algorithm ranks your site

The inner workings of the Google algorithm are clouded in mystery, but we do know that five major ranking factors play an outsized role in search ranking: backlinks, freshness, keywords, page experience, and subject matter authority. Here’s how these impact search ranking:


When websites with topical authority contain links to your web pages, your site can rank higher on SERPs. For example, backlinks might appear in an authoritative site’s blog post or high-quality product reviews about your products. Create useful, compelling content that other reputable websites want to link to to improve your odds of accruing backlinks. 


The algorithm favors freshly updated pages. This factor is context-dependent, however, meaning some blog posts don’t need to be the newest to be relevant. If you’re looking up the definition of the term like “what does magstripe mean,” for example, an older page might outrank a newer page because it scores higher on other measures. Regularly check your content for accuracy and update popular posts as needed to maintain freshness. 


In general, the more often relevant keywords appear on an indexed page, the higher it ranks for those keywords. Keywords must also appear in the page title and meta title, in addition to the body content. You can optimize your pages to increase relevant keyword mentions; however, too many repeated keywords (i.e., keyword stuffing) can actually be detrimental. Aim to incorporate keywords naturally into sentences to avoid being dinged for keyword stuffing. 

Page experience

Google puts a high value on user experience (UX). The algorithm measures page loading speed, determines a site’s ease of navigation, checks for mobile accessibility, and looks for meta tags that match page content. Avoid using large images that take a long time to load or stuffing your web pages with ads to keep the user experience enjoyable.

So, how do you stand out if you’re an ecommerce site? Kyle Risley, SEO lead at Shopify, suggests you sell something that is unique, but is still searched for. “These queries will be easier to rank for. This is effectively identifying an underserved market/niche. If they go this route, on-page optimization will be their most valuable task.” Another option would be to sell something in a competitive niche. Kyle says, “Ranking in this scenario will require on-page optimization and backlink earning. The quality and quantity of the backlinks needed will depend on backlink profiles of the competing sites in the niche.” He also reminds stores that page experience will always be important.

Important Google algorithm updates

Google continuously tweaks its search ranking rules. Some are major algorithm updates, others unpublicized minor updates that hardly anyone notices. 

On average, two to three major updates occur each year and are referred to as broad core algorithm updates. They may have a dramatic impact on search result rankings. If you notice big changes in SEO ranking performance, core updates could be the reason. 

Here’s a brief Google algorithm update history featuring the most important updates:


The Panda algorithm update came in early 2011 and was integrated into the core algorithm in 2016. Panda evaluates a web page and assigns a quality score, then downranks a page that indulges in spammy content like duplicated pages, plagiarism, and keyword stuffing.


Penguin was released in Spring 2012 and takes aim at inauthentic link-building methods, such as purchasing backlinks from link farms. It also analyzes pages for irrelevancy and spam links. 


This 2013 update was a response to keyword stuffing and superficial content. It improved the interpretation of search queries by using natural language processing to infer the user’s intent. 

Thanks to Hummingbird, a page can be upranked even if it doesn’t exactly match the search terms because the semantics (synonyms and adjacent terms) on the web page relate closely to the search meaning. 


In 2014, Google released an algorithm that improved the accuracy of local search results and tied them to other ranking signals. This is noticeable in Google Maps searches and web searches.

Mobile-first indexing

In April 2015, Google reorganized its index, prioritizing mobile-facing versions of websites over desktop versions. Sites lacking mobile presentation or mobile functionality were downranked. The official announcement of mobile-first indexing came in 2016, and newer updates in 2018 and 2020 cemented the importance of fast, usable mobile web pages. Mobile-first indexing changed which version of a page was used for scoring and ranking.


In October 2015, RankBrain, an offshoot of the Hummingbird update, tackled three search result problems: weak relevance to the search query, thin content quality, and poor user experience. RankBrain uses machine learning to probe the meanings behind search queries. 

Google doesn’t divulge the inner workings of RankBrain, but it has said it is the third most important factor used to rank result pages. Analysts surmise that RankBrain factors in search term context, which probably means semantic processing and considering the user’s search history. 

Intrusive Interstitials Update

In 2016, Google responded to intrusive interstitials—annoying pop-up ads—obscuring web page content in its search index. This doesn’t mean that all interstitials are bad or that they hurt search engine rankings. Abuse of the end-user experience is especially egregious on mobile devices with smaller screens. Offending pages, “the worst offenders,” were downranked, starting in 2017.


This October 2019 update leans heavily on natural language processing to identify and demote poorly written, unfocused text with shoddy context, and reward well-written content. BERT is the culmination of previous updates like Panda, Hummingbird, and RankBrain. 

Google algorithm FAQ

How often does Google update its search algorithm?

Search algorithms are updated thousands of times per year. Most of the Google algorithm changes go unpublicized; however, significant updates to Google’s core algorithm (known as a core update) occur every few months.

Does Google penalize websites for violating its algorithm guidelines?

Google penalizes websites attempting to manipulate the system, resulting in lower search rankings or even removal from the index. Penalties come in two forms: automatic algorithmic penalties for spam and SEO manipulation and manual actions from Google’s human reviewers for violating webmaster guidelines.

How can I recover from a Google algorithm penalty?

If you suspect a penalty, check Google Search Console for manual actions affecting your site’s ranking. Identify and address the issue, then request reconsideration from Google to lift the penalty and expect improved Google rankings.