What is a Google Algorithm Update?

A Google algorithm update essentially means alterations have been made by Google in terms of how they assess the rankings of websites, based on a multitude of factors.

Google is ever-tweaking and updating their algorithm, therefore positions of webpages change in the search engine results page (SERP). So, for you, your website’s rankings may change. If so, organic traffic to your site could be affected either positively or negatively as a result.

Google is constantly making small changes but a few times a year they roll out a major algorithm update. What were the major ones in the past few years? And which came first? In this post, we present a short history of confirmed Google algorithm updates from Panda through to the recent June core update in 2019.

Timeline beautifully created by ‘JESSemrush’

List of Google Algorithm Updates

What is the May 2020 Core Update?

The May 2020 Core Update was the latest of Google’s broad core algorithm updates, the second one of the year, and the first core update to have been rolled out since the COVID-19 pandemic. Just like the January core update, this one was announced in advance via the Google Search Liaison account on Twitter, but once again not far in advance as it begun rolling out no less than 90 minutes later.

When did the May 2020 Core Update happen?

This core update began on 4th May 2020, with guidance from Google that it could take a period of one to two weeks to fully roll out, as is typical. Moz reported that the most impact from this update was particularly felt between 4th May and 6th May 2020.

What did the May 2020 Core Update affect?

With reportedly the second highest rankings flux from a core update since Medic in August 2018, early reaction to the May 2020 Core Update saw publishers and webmasters in spaces such as news, health and medical, and finance observe significant ranking shifts and, often, complaints of negative movements that led to traffic declines. A notable example was Search Engine Roundtable, who themselves provide news coverage of Google’s algorithm updates and the aftermath of them, who would see a 30% decline in traffic from Google.

A connection may have been made between the May 2020 update and Google deindexing pages of a website. In this same month, John Mueller at Google spoke of deindexing on a hangout, essentially stating Google may no longer want to index particular parts of a site that don’t meet their benchmark of quality, so not to expect all content to be indexed, even if requested by a webmaster. How that relates to this algorithm is sites that were hit in some cases also found themselves with less indexed pages. Going back to Search Engine Roundtable, their drop in traffic was accompanied by a 35% drop in indexed pages.

An informative piece by onely.com on Google’s approach to rendering certainly suggests updates like this one are having an influence on indexing trends. This analysis reports an increase in JavaScript indexing this month, with HTML indexing declining as a result, and suggests the increasing expense for search engines like Google to parse and render webpages is reason they will have to determine, from a quality point of view, the most worthy content to index.

What is the January 2020 Core Update?

The January 2020 Core Update was another in a series of pre-announced algorithm updates and the first of the new year. The announcement came, as per usual, via Twitter and approximately one hour later, Google went on to state that the update was live and rolling out.

When did the January 2020 Core Update happen?

This core update began on 13th January 2020 and was reported to be largely complete within only a few days but with subsequent fluctuations expected over a period of two weeks.

What did the January 2020 Core Update affect?

Data collated from various sources including RankRanger, SearchMetrics and Sistrix illustrated that this update was a significant one with an impact to a large number of sites, with a clear indication that YMYL (Your Money or Your Life) sites – specifically those in health and finance niches – experienced the most volatility.

Sistrix analysis suggested that these YMYL sites and their topics had, with this core update, been re-evaluated by Google, with domains previously affected by past algorithm updates the more likely to be impacted again. The January 2020 update was also likened to prior updates by Google in September and March of 2019 in its characteristics of scrutinising the health/medical space with a focus on trustworthiness.

What is the BERT Update?

BERT was announced by Google as an algorithm update on the week it was rolling out, who described it as a “significant improvement to how we understand queries, representing the biggest leap forward in the past five years, and one of the biggest leaps forward in the history of Search.” In 2018, Google introduced a natural language processing technique called Bidirectional Encoder Representations from Transformers (that’s where ‘BERT’ comes from) and fast forward to 2019 this algorithm update marked those BERT models being applied to search.

When did the BERT Update happen?

This Google update officially came into effect on 25th October 2019.

What did the BERT Update affect?

As confirmed by Google, on launch BERT would impact 1 in 10 of all search queries in the U.S. in English (with plans to introduce the same to more locales over time) and would, at the time, be the most significant change in search since Google released RankBrain.

BERT models were applied to both ranking results and featured snippets with the intention to help searchers find more useful information. With the update, for a given search query Google stated their algorithm would now process words of that query in relation to all of the other words in the sentence, rather than the traditional order of one-by-one. Essentially, this was Google deeming context as key to understanding the intent behind search queries.

On the announcement blog post, Google offered some examples of queries where BERT was now helping them pick up on nuances of human language. The query shown in the screenshot above was one such example: “Can you get medicine for someone pharmacy” – here, Google demonstrate that “for someone” is an important part of the search the user made and this element of the query is now understood by BERT when previously it was missed (see Before in the screenshot).


What is the September 2019 Core Update?

This Google update was another in a series of algorithm tweaks that Google would give a specific name to (rather than staying coy and leaving the name up to the SEO community). This update was also announced in advance by Google but only on the same day it was rolled out.

The announcement came via Twitter, as did a further update to say the September 2019 Core Update had gone live:

When did the September 2019 Core Update happen?

This core update began on 24th September 2019 and speculation was it ran through Google’s birthday on the 27th.

What did the September 2019 Core Update affect?

Based off early indications in the first 24 hours, the update was slow to roll out but after a few days more of an impact was beginning to be felt. For one, the Daily Mail, who had been enormously impacted by the June 2019 Core Update, were amongst the big winners in the UK. Conversely, some news-related websites were negatively impacted by this update. Overall, it appears that the most volatility following this update was with sites in the health/medical space. Like the updates that preceded this one, clearly E-A-T – expertise, authority and trustworthiness – played a part once again.

What is the June 2019 Core Update?

The June update was significant in that Google gave it a name again (see: March update) and in a rather unprecedented move announced the update in advance on Twitter. Not only did they confirm exactly when it began, but Google also told us when it had finished rolling out.

When did the June 2019 Core Update happen?

This update had a 5-day roll out between 3rd June and 8th June 2019.

What did the June 2019 Core Update affect?

Early analysis reported that the field of domains affected by this algorithm update was wide-ranging and included news sites, retail sites and others classed as YMYL (Your Money or Your Life) – those involving financial transactions or health/lifestyle.

A significant impact was felt by certain websites such as the UK news site Daily Mail which publicly revealed they had lost 50% of their daily traffic. The principles of E-A-T – expertise, authority and trustworthiness – seemed to be at play again here (see: Medic update), now with close emphasis to the Trust element.

What is the March 2019 Core Update?

Google announced this core update via Twitter which was significant because that was still quite a rare occurrence. This was tweeted during the week the update was rolled out, but not in advance. Google also gave this update a name – the March 2019 Core Update. Perhaps this was a move to control the names the SEO community were giving to these updates.

When did the March 2019 Core Update happen?

12th March 2019.

What did the March 2019 Core Update affect?

Specifics were not divulged as to what this update entailed, however the effects felt were major for websites in the medical or health space. The March update was speculated to be a possible reversal of or tweaking to the previous Medic update from August 2018.

The analysis of the update showed Google continued to fine-tune search results for sensitive topics such as health-related ones; in this industry, it was observed that some of the biggest winners from the previous update were now amongst the biggest losers following the latest one. A follow on from the Medic update, it was clear that this update further cemented the need for E-A-T (Expertise, Authority & Trust) and strong branding in the eyes of Google.

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What is the Medic/E-A-T Update?

The Google Medic/E-A-T Update was a “broad core algorithm update” which affected websites based on their E-A-T (Expertise, Authority & Trust) and YMYL (Your Money Your Life) website quality.

Google stated that they carry out these updates “several times per year.” You can see their official tweet regarding the update below:

When did the Medic/E-A-T Update happen?

1st August 2018.

What did Medic/E-A-T Update affect?

According to Google, this was a “global” update, which suggests every niche and every type of site could have been affected. However, further research suggested the Google Medic/E-A-T update strongly impacted medical websites (hence the name, which wasn’t officially given by Google).

A survey of more than 300 affected sites conducted early on in the days that followed the update categorised approximately 42% as health-related sites. The update was said to concentrate on YMYL industries, health, of course, being a large part of that, but websites in the fields of finance, gambling, travel and more were also affected.

What is the Mobile Speed Update?

The Mobile Speed Update was a page speed algorithm refresh specific to mobile devices. This update was announced in advance in January, several months before the rollout and it arrived a few months after the move to Mobile-First Indexing.

When did the Mobile Speed Update happen?

9th July 2018.

What did the Mobile Speed Update affect?

According to Google in their blog post, “The “Speed Update,” as we’re calling it, will only affect pages that deliver the slowest experience to users and will only affect a small percentage of queries.”

This refresh affected websites with poor mobile page speed and unresponsive or poorly optimised mobile websites. With page speed now becoming a ranking factor, sites with poor user experience in this regard had, and still do have, the potential to be ranked lower than alternative pages with better speed on mobile. From this point, the update meant that for the most competitive search terms page speed was imperative in order to be ranked higher in Google’s index.

More information can be found at https://webmasters.googleblog.com/2018/01/using-page-speed-in-mobile-search.html

What is the Mobile-First-Index?

After a year and a half of experimentation, Google announced that mobile-first indexing was being rolled out. The Google index was now being crawled and created based on the mobile experience of websites.

When did the Mobile-First-Index happen?

26th March 2018.

What did the Mobile-First-Index affect?

The update meant that sites following the ‘best practices for mobile-first indexing’ were moved over and notified as such via Google Search Console. Prior to this, only a limited number of sites had been switched to this indexing process. Many sites were now affected from this point, placing increased importance on the mobile version of web pages. On mobile-first indexing, Google said:

“To recap, our crawling, indexing, and ranking systems have typically used the desktop version of a page’s content, which may cause issues for mobile searchers when that version is vastly different from the mobile version. Mobile-first indexing means that we’ll use the mobile version of the page for indexing and ranking, to better help our — primarily mobile — users find what they’re looking for.”

What is the Brackets Core Update?

Google pushed out this core update without a name, later coined the Brackets Update, which was ongoing for close to 2 weeks. The name will make more sense to a North American audience; the update was reported during the NCAA basketball championships which is also known as ‘March Madness’.

When did the Brackets Core Update happen?

7th March 2018.

What did the Brackets Core Update affect?

The update appeared to focus on quality and Google’s assessment of it over the long term as related to sites in their index. It emphasised that Google can reward sites with high-quality content which can be based on a multitude of factors; engaging content that attracts links and strong trust signals from the expertise of an author as two examples. A loss or gain in rich snippets was said to be a warning sign of this quality-related update.

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What is the Mobile Friendly 2 Update?

Once again Google rolled out a ranking signal boost for mobile-friendly websites catered to mobile search, a follow on from the original mobile-friendly update a year or so prior. This was announced by Google 2 months before being rolled out:

When did the Mobile Friendly 2 Update happen?

12th May 2016.

What did the Mobile Friendly 2 Update affect?

As is self-explanatory, this update reinforced the need for websites in the Google index to be mobile friendly and in theory increased the effect of this ranking signal. This algorithm signal was said to be assessed page by page and therefore could well have taken some time to fully roll out. Google assured the SEO community that sites will not be impacted by the update if a mobile-friendly strategy is already in place.

What is RankBrain?

Google introduced RankBrain as a machine learning AI system built into their search algorithm. It was revealed that this technology had been in use for a few months prior to the announcement.

When did RankBrain happen?

26th October 2015.

What did RankBrain affect?

This machine-learning artificial intelligence system was said to aid Google in processing their search results; essentially a smart computer system designed to sort through the vast number of pages in Google’s index and find the right ones for the user’s search query.

Google named it the 3rd most important factor for ranking a webpage. Of course, this ‘update’ gave us further insight into the various factors at play when Google selects webpage results – and demonstrates that Google’s understanding of search queries continues to improve – but it wasn’t one where effects were felt by specific websites.

What is the Quality Update?

Google confirmed – without ever going into specifics – an update that impacted “quality signals” hence the name it was eventually dubbed (starting out life as the Phantom Update because Google wasn’t acknowledging it for a while).

When did the Quality Update happen?

3rd May 2015.

What did the Quality Update affect?

Google did share that this update was about how its search algorithm processes quality signals. It was already known that Google assesses the quality of a webpage based on a wide range of factors, so it was speculated that this update upped the importance of one or more of those factors.

It appears that no particular industry or group of sites were directly affected as one here, instead this was a broad update that could potentially affect any site – HubPages were amongst those it did hit; the ‘mini-blog’ site reportedly lost 22% of its traffic on the day of this algorithm update compared with the week prior.

What is Mobilegeddon?

This was Google’s Mobile Update, announced in advance (again, a rare occurrence) and given the name “Mobilegeddon” by the SEO community. Google stated that with this update they would be “expanding the use of mobile-friendliness as a ranking signal” and thus display more mobile-friendly websites in their search results.

When did Mobilegeddon happen?

22nd April 2015.

What did Mobilegeddon affect?

Even before the rollout of this update, which Google suggested could complete in a matter of days or weeks, some mobile-friendly sites were marked as such in the SERPs – users would increasingly begin to see this tag on sites in their list of results.

Analysis by Moz measured the short-term impact as smaller than expected and reported that sites late to the mobile party were able to make their changes and be reprocessed in Google quickly. Overall this update showed the importance of, and Google’s public stance on, mobile-friendly sites and the advantage they would have going forward.

What is the Pigeon Update?

The (unofficially named) Pigeon update overhauled Google’s local search algorithm with noticeable changes on both Google Maps and Web search results.

When did the Pigeon Update happen?

24th July 2014 (expanded in December 2014).

What did the Pigeon Update affect?

The update was rolled out for US English results first with the aim to provide a great experience in local search in terms of usefulness and relevance. Google shared with Search Engine Land that the new local search algorithm would now include the wide array of ranking signals used in traditional search and “improve [Google’s] distance and location ranking parameters”.

Pigeon would make the flight once again in December of 2014 when Google rolled it out in the UK, Canada, Australia and beyond (all English-speaking locales).

What is the Penguin Update?

This “Webspam Update”, officially named Penguin, was multifaceted with various instances of the update over a period of more than 4 years. It first came about following speculation of Google introducing new penalties for over-optimising webpages.

When did the Penguin Update happen?

24th April 2012 to 6th October 2016.

What did the Penguin Update affect?

Penguin & Penguin 1.1

The first update back in 2012 would adjust several spam factors, penalising webpages that stuffed keywords or had too many ads above the fold, for example. Google announced the update by describing it as “another step to reward high-quality sites” and “targeted at webspam” as the aim of the update was to decrease rankings for sites believed to be violating their quality guidelines.

Later in the same year, Google rolled out Penguin 1.1 which was announced by Matt Cutts via Twitter and described as a “data refresh”. Another such data update would also happen in October 2012.

Penguin 2.0 & 2.1

Penguin 2.0 (the fourth Penguin update so sometimes referred to as Penguin 4) arrived in May 2013, and going off comments by Matt Cutts was speculated to be a major update that would go deeper than the first generation update. The impact, though, turned out to be moderate, as did Penguin 2.1 which was a data update rolled out in October the same year.

Penguin 3.0 & Everflux

Penguin 3.0 and Penguin Everflux followed but would take place more than one year after the prior updates. Pierre Far from Google confirmed that Penguin 3.0 had affected “fewer than 1% of queries in US English search results.”, so it was speculated to be a data refresh rather than a full-blown algorithm update. With Everflux, this marked the beginning of Google now updating the Penguin algorithm continuously.

Penguin 4.0

The penguin would return in two parts in 2016. Google announced the new Penguin 4.0 prior to its rollout; phase 1 was launched over a few days, followed by phase 2 which reversed all previous Penguin penalties.

Penguin 4.0 was described as a more gentle version of Penguin as it devalued bad links rather than the penalising of sites observed in the past. As such with Penguin 4.0 there were wide reports of recoveries from the negative effects felt from Penguin.

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What is the Panda Update?

Panda was a major algorithm update (originally referred to as “Farmer”) that had a significant impact, introduced to tackle sites with quality issues – such as content farms, pages with thin content or high ad-to-content ratios, etc.

When did the Panda Update happen?

23rd February 2011 to 17th July 2015.

What did the Panda Update affect?


Panda had close to 30 different roll-outs in this period. When it was first announced Google confirmed that it was big; noticeably impacting 11.8% of Google queries. Searchmetrics, SISTRIX and others in the SEO community analysed the impact and found that the update heavily hit low quality “article marketing” sites, and had other general observations:

“…the most heavily hit sites had less attractive designs, more intrusive ads, inflated word counts, low editorial standards, repetitive phrasing, poor research, and in general didn’t come across as helpful or trustworthy.”

Quality in 23 Questions

Amit Singhal, with Google at this time, confirmed that the algorithm was created with a comparison of traditional ranking signals to human quality rankings (questions they would ask human quality raters about perceptions of a website from its trustworthiness to number of ads, etc). Singhal would go on to release 23 questions of this type that a webmaster could ask themselves about their site in order to improve its quality in the eyes of Google.

Panda as a core ranking signal

The many different reintroductions of Panda creates some confusion over their impact and many are thought to be minor updates and data refreshes, but some of them will have inevitably included new quality indicators along the way. Panda was run externally from Google’s core algorithm through many of these updates we’ve covered, but as of the most recent rollout, Google confirmed that Panda is now built into Google’s algorithm and is one of their core ranking signals.

Concerned about an algorithm update?

Do you think you might have been hit by one or more of these Google algorithm updates? Check out the ebook: 5 Free Tools To Check If Your Website Was Affected by Google Algorithm Updates.

Alternatively, speak to us about a free post-algorithm audit of your site.

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