Google tweaks its search algorithms at least once a day, with the aim of providing increasingly accurate results for every search query.
Such a rapid pace of change can cause concern among marketers and it is easy to see why. Organic search drives over 50% of all website traffic. So, if Google changes the rules, it can fundamentally affect the quantity and quality of online visits that any business receives.
Equally, there are those in the SEO industry who pay close attention to these updates in the hope they can “crack the algorithm”. After all, knowing how Google evaluates websites could provide a very profitable competitive advantage!
The 2024 Google documentation leak provided rare insights into Google’s algorithm, but marketers must still be prepared for constant change. This is particularly true in the AI age, as Google makes rapid changes to try and fend off new competition. For instance, Google’s rushed launch of AI overviews in search results led to headlines such as “Google advises users to run with scissors, cook with glue and eat rocks.” Marketers are always on high alert, especially when Google makes mistakes like these.
Among the tiny tweaks indecipherable to the naked eye, the search giant has also launched a small number of what it terms “broad core algorithm updates” since 2018. These are announced via the Search Liaison X account, a role held by renowned SEO expert Danny Sullivan. The creation of this role at Google was a welcome step towards providing transparency into a channel that is the lifeblood of so many online businesses.
In general, Google developments nowadays aim to reward sites that provide a good user experience, rather than punishing those that take shortcuts to get to the top of the search engine results page (SERP).
To understand how we got here, it is worth quickly recapping the most important historical Google updates. Next, this article will assess the new, markedly different age of algorithm updates we live in today with a focus on “broad core changes” that have now become habitual in the industry.
- Major Google algorithm updates: a brief history
- Panda
- Penquin
- Hummingbird
- RankBrain
- Possum
- The Mobile-First Index
- BERT update
- MUM (Multitask Unified Model)
- Google core updates
- The 2018 core updates
- E-E-A-T
- May 2020 core update
- June and July 2021 core updates
- March 2023 core update
- August 2024 core update
Major Google algorithm updates: a brief history
Panda
Initial launch: 2011
In a sentence: Panda was a major algorithm update (with many iterations since its inception) that clamped down on content farms and sites with low-quality content.
Who did/does it affect? The initial Panda update affected about 12% of all queries and saw sites with thin content or high ad-to-text ratios drop in the rankings. Panda has been updated consistently since 2011 to include new data signals, including user engagement metrics (e.g., bounce rates and time spent on site), content comprehensiveness, authoritativeness, and site architecture. Its data is processed outside of the main Google index, much like that of the Penguin algorithm.
Penquin
Initial launch: 2012
In a sentence: Known as the “Webspam Update” at first, Penguin targeted spam techniques that had helped sites climb the rankings. These techniques included keyword stuffing and buying backlinks.
Who did/does it affect? It affected 3.1% of English queries at launch, but this soon expanded to a larger data set. Penguin has sent ripples through the industry to rival any other set of updates, and it now works in real time (rather than at intervals) to fine-tune the search results.
Hummingbird
Initial launch: 2013
In a sentence: Perhaps one of the biggest core algorithm updates of all time, Hummingbird ushered in a new era of “semantic search”, powered by deeper understanding of user intent and Google’s vast Knowledge Graph.
Who did/does it affect? Hummingbird has affected how all queries are interpreted, but it has particularly benefited companies that work to create conversational search experiences. Google labeled this update “Hummingbird” because it is “precise and fast”.
RankBrain
Initial launch: 2015
In a sentence: Google announced in October 2015 that it had started using machine learning as a core part of its algorithm, through a technology it coined “RankBrain”.
Who did/does it affect? This affected pretty much everyone! RankBrain was said to be the third-most important aspect of the core algorithm, and its importance has been cemented over time. This means Google’s algorithms can adjust their assumptions based on user feedback in real time to provide increasingly accurate results.
Possum
Initial launch: 2016
In a sentence: Possum was an update that focused on improving the quality of local results, based on the exact location of the searcher and the quality of available results.
Who did/does it affect? Many businesses that sit just outside of a city’s geographical limits saw an increase in their visibility, as Google relaxed the fixed rules it previously had in place. Users also saw more variety in the search results, based on specific modifiers or the order of words in their search query.
The Mobile-First Index
Initial launch: 2018
In a sentence: Google starts using the mobile version of content for its search index, rather than the desktop version. This seismic shift marked the move to a mobile-first world.
Who did/does it affect? The roll-out has been very gradual, but all websites will be affected worldwide. Although it is taking time to get right, Google is completely committed to making this change. Webmasters should be monitoring Google crawl activity to see the impact of their shift to mobile-first indexing.
These are just some of the headline acts, but they’re the ones that have done most to shape the current landscape. There is an exhaustive list of all updates up to the present day at Moz.
BERT update
Initial launch: October 2019
In a sentence: The BERT (Bidirectional Encoder Representations from Transformers) update helped Google better understand natural language and context within search queries.
Who did/does it affect? This update impacted about 10% of all search queries, and it was particularly beneficial for understanding long, conversational queries. This provided marketers with new opportunities to create excellent content without an over-reliance on using exact match keywords within their copy. BERT has also been an important step towards the more conversational Google experience we know today.
MUM (Multitask Unified Model)
Initial launch: May 2021
In a sentence: MUM is a transformative AI-driven update that allows Google to better understand and process complex search queries by leveraging multimodal data (text, images, and video) across multiple languages.
Who did/does it affect? MUM enhances Google’s ability to answer complex search queries that previously required multiple searches. For example, it can compare and synthesize data from various formats and languages to answer difficult queries, such as travel planning or product comparisons. This makes it a major update for industries dealing with complex, multi-step queries, such as travel, health, and ecommerce.
Google core updates
Google’s core updates have become a regular feature of its algorithm, with new releases several times a year. They are significant and regular enough to merit their own section of our guide to Google’s algorithm changes.
These updates are designed to improve how Google evaluates content and determines rankings. Unlike smaller, targeted updates, core updates affect a wide range of search queries, industries, and languages, meaning they can cause significant fluctuations in rankings across the web.
The 2018 core updates
MozCast, which measures the level of volatility in search results, recorded very high levels of activity between August 1 and 2 2018, suggesting that Google was making some big changes. This was confirmed by a tweet from Google’s Search Liaison.
At first glance, this appears to give very little away. The update was described as a “broad core” change and the later advice to webmasters was to “create great content”.
As noted in the introduction to this article, Google’s aim is to reward sites that provide useful, relevant content, rather than punishing sites that do not do so. Google never wanted to spend valuable engineering resources creating punitive updates, but some elements of the SEO industry necessitated the action.
The net result may be the same in some instances (if some sites are rewarded, others need to drop in the rankings), but the objective is significantly different.
E-E-A-T
In recent years, Google has tried to help site owners understand this concept by emphasizing the Google E-E-A-T (Experience, Expertise, Authoritativeness, and Trustworthiness) framework, particularly in its core updates.
Google’s broad core updates reward websites that demonstrate strong E-E-A-T signals. For instance, sites that provide clear author information, cite reputable sources, and offer real-world expertise are more likely to rank well.
Experience was added in late 2022, expanding Google's focus to consider whether the content creator has first-hand experience with the topic. This shift especially benefits industries where personal insight matters, like product reviews or health advice?.
Expertise and Authoritativeness relate to the creator’s credentials and the authoritativeness of the site or content itself. Google wants to ensure that content comes from individuals or organizations with recognized expertise in the field, particularly for YMYL (Your Money or Your Life) topics, such as health and finance. It also checks whether the website or page is a recognized authority or go-to source for the topic.
Trustworthiness is a key measure of whether the site is safe, accurate, and credible. This is particularly important for sites offering advice, news, or transactional content, where accuracy is critical to user trust. Quality raters look at the creator, content, and website to assess trustworthiness.
May 2020 core update
Launch: May 2020
Impact: The May 2020 update was particularly impactful due to the timing, coming in the midst of the COVID-19 pandemic. It led to major shifts across sectors, with health, travel, and ecommerce sites being the most affected. Some reports indicated that sites with outdated or misleading content saw significant drops in traffic and rankings.
What it meant for marketers: Marketers needed to pay attention to content freshness and relevance, particularly in industries affected by the pandemic. The update highlighted the importance of providing up-to-date information, especially for industries like news, health, and ecommerce, where consumer behavior and needs were rapidly changing.
June and July 2021 core updates
Launch: June 2021 and July 2021
Impact: These updates were closely related to Google’s Page Experience Update, which introduced Core Web Vitals as ranking factors. These metrics, which include page load time, interactivity, and visual stability, were designed to improve user experience across mobile and desktop devices.
What it meant for marketers: Marketers needed to focus on technical SEO and website performance. Improving Core Web Vitals became essential for maintaining rankings. Businesses had to invest in improving page speed, reducing layout shifts, and ensuring a seamless experience across devices. It also reinforced the need to optimize for mobile as more users shifted to mobile browsing?.
March 2023 core update
Launch: March 2023
Impact: The March 2023 core update was more volatile than expected, impacting a wide range of websites. Data from SEMrush showed large movements in YMYL sectors, especially health, where E-E-A-T became even more crucial. This update also reinforced Google's focus on rewarding firsthand experience?.
What it meant for marketers: For marketers, the March 2023 update emphasized the need to show firsthand experience and authority in content. Marketers had to revisit how they showcased expertise and ensure that author information and credentials were prominently displayed. Google increasingly favored content creators with verifiable expertise
August 2024 core update
Launch: August 2024
Impact: The August 2024 core update was designed to reward small and independent publishers by promoting original, user-first content. Google aimed to surface the best of the web, focusing on authenticity and helpfulness while penalizing clickbait or overly optimized content. Reports fromSimilarweb noted significant ranking shifts across smaller sites, with many previously penalized websites seeing recovery?.
What it meant for marketers: This update reaffirmed Google’s commitment to rewarding genuine content and providing opportunities for smaller publishers. Marketers needed to focus on producing authentic, original content that resonated with users rather than content created solely to rank well. This update was a reminder that overly optimized, clickbait-style content could lose visibility if it did not genuinely serve the user?.
Chart from Similarweb showing August 2024 activity
How should marketers respond to these core updates?
As with all Google updates, any fluctuations in impressions, clickthrough rates, or rankings can be instructive. If a site has been affected by the changes, that can shed light on how Google views your content.
In addition, any marketers who want to understand what Google means by “quality content” should read the Search Quality Raters Guidelines.
It must be noted that this is not a direct insight into how Google’s algorithm works, and the guidelines do not shape the results we see. That said, they do tell us what Google wants its algorithms to deliver. As such, they are an essential reference point for marketers looking to prepare their content for the future of search.
By monitoring and adjusting your content strategy based on these updates, you can ensure your site aligns with Google's evolving standards. Here are actionable steps for responding to these changes:
Monitor Key Metrics: Track impressions, click-through rates, and rankings for insights into update impacts.
Benchmark Performance: Compare metrics before and after updates to identify affected areas.
Focus on Content Quality: Improve content depth, relevance, and authoritativeness to meet Google’s standards.
Adapt SEO Practices: Regularly update your content and technical SEO based on evolving quality criteria and user experience requirements.
By implementing these steps, marketers can better align their strategies with Google’s expectations and maintain or improve their rankings post-update.
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