Google Core Update June 2021 – The Summer of Google Updates

Google has taken its time because only now, almost halfway through the year, has the first officially confirmed Core Update of 2021 started. We take a look at the effects of this update, and consider what it going to be quite the summer of updates.

The Core Updates, as they are named by Google, are deep changes in the ranking algorithm, which is responsible for creating the search results. While there are minor updates almost every day, it is the Core Updates that often stir-up entire search result pages (SERPs) and business sectors.

The last Core Update officially confirmed by Google ran in December 2020, almost six months ago. Google has taken an unusually long time to announce the current Core Update June 2021, but here it is, announced on June 2nd 2021.

Google announces Core Update on Tiwtter

In the meantime, Google has also confirmed that the update is already being distributed to its data centers.

We are starting to see the first changes in the search results. Early reactions appear to be visible in Visibility Index data starting on the 7th.

8th June 2021: A number of candidate examples are shown below and this post will be reviewed daily during the Core Update rollout and updated to show the current status, with domain lists where necessary.

11th June 2021: Data updated (below) following the end of changes seen in the SERPs, and the possible end of the roll-out.

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The summer of Google updates

Just as the June 2021 core update is announced, Google has already announced another core update for next month, July 2021. The reason, they say, is that they have not yet fully completed all the internal preparation work. As a result, one part will be rolled out this month, the other part coming after the June rollout is complete, in the following month.

This means we can expect a summer of Google updates because in addition to the two core updates, there is also the Page Experience Update that has been announced for mid-June.

Here are the summer of ’21’s planned updates at a glance:

  • June Core Update: has been rolling out since June 3rd, 2021. Effects can be seen in the Google SERPs. This is a “Classic” core update.
  • July Core Update: the second part of the June update. No details are known yet, but it can be assumed that there will be major shifts.
  • Page Experience Update: the update announced last year, in which a number of user experience factors are taken into account. This is related to the now well-known Core Web Vital values.

The expectations of the effects of the Page Experience Update should not be overstated: On the one hand, Google will roll out the update gradually and slowly over several months. On the other hand, Google has repeatedly reduced the emphasis on the page experience factor in recent months. Currently only a “tie breaker” is spoken of – which only becomes important when all other ranking factors are equivalent (which in fact, will almost never happen).

Core Update June 2021 differs from other ranking changes

Even before this Core Update, there was quite a lot of movement in the Google search results over the last few weeks, and it’s very important now to be able to clearly separate these changes from the Core Update in order to be able to correctly assess cause and effect.

Changes in visibility in the last month are characteristic of changes as we see them with these three domains:

Recent movements in UK SERPS. Three example domains showing a similar pattern.

All three domains (, and work in a comparable content environment. These domains also don’t necessarily have unique content. They compete.

It is noticeable that the visibility curves of the domains have a similar ‘heartbeat’. Visibility is lost on the same date, but later regained on the same date.

In a similar manner, from a different sector, you can see similar effects. In this case, from the travel industry.

Recent movements in UK SERPS. Three example domains showing a similar pattern.

These three domains (, and also show clear parallels in the development of their visibility just a week ago. It is also important to remember that the Visibility Index measures SEO success and not fluctuations in demand.

These visibility curves can therefore be traced back to real changes in the ranking of the domains. It’s not that the search volume for the domain’s ranking keywords changed in the short term so when assessing domain changes, especially during this Core Update, it’s important to understand your data-source:

  • Daily updates: Due to the many shifts in rankings that happened recently, and just a few days apart, daily updates are essential to reliably identify the cause.
  • No dependence on changes in demand: In order to be able to measure SEO success, external factors must be removed from consideration. Data from Google Search Console measures demand (as seen currently, and related to the pandemic, with a rapidly increasing search volume in the travel industry). More on this.

How do I know when a domain has been affected by the Core Update?

Now that we have clarified in detail what the visibility history of domains that are not affected by this core update look like, we now turn to examples that have been affected by this update. First a domain that has lost visibility during this Core Update:

Domain visibility losses at show in the Visibility Index graph

It’s clear to see the sharp fall in the previously stable Visibility Index from the 6th June to the 7th and through to the 8th of June. Other domains with losses might not be as clear-cut as this one. There are also domains that have made similar levels of gain in the other direction:

Domain visibility gains at show in the Visibility Index graph

Visibility redistributed within industry sectors

In most industries it can be seen that there are both winners and losers. As with the last Core Updates, Google is not concerned with giving entire industries more or less visibility, rather individual market participants become more or less visible.

This can be observed, for example at and here:

Two domains operating in much the same sector, show in a SISTRIX visibility graphic

While gained significant points of visibility through the Core Update,, operating in the same sector, gave up visibility. However, to get a better look at where gained from, we can analyse the keyword gains and losses and list the domains from which the gains were made.

Table showing domains from which visibility has been gained.

(We are still developing this feature for a more detailed analysis of losses / gains in visibility. Please keep that in mind and consider it as a very early beta, but the link to the feature, via the screenshot, is already working and useful. Please send errors and/or anomalies to

Winners and Losers: Core Update June 2021

We have analysed and summarised data at various points during this Core Update and details are shown below.

Update 8th June 2021

Our first data-set, dated 8th June, is now available. Below you’ll find a list of 10 domain winners and losers by percentage and absolute values. The list is curated to remove domain movements that are obviously not part of the Core Update (migrations etc.)

Google Core Update June 2021: UK Winners (Percentage, SISTRIX Data: 08/06/2021)
Domain03.06.202108.06.2021VI Change
Google Core Update June 2021: UK Losers (Percentage, SISTRIX Data: 08/06/2021)
Domain03.06.202108.06.2021VI Change

Update 11th June 2021

The June 2021 core update has come to an end: we are no longer seeing any major changes in most of the affected domains from yesterday to today. This means that today’s daily visibility values are a good basis for analysing the overall shifts.

Health industry below average changes

In previous core updates, projects around the topic of health were often heavily affected: both serious content and semi-serious quack projects. This is hardly noticeable with this core update.

The second pillar of the YMYL (Your Money, Your Life) project is also affected below average: there are a few financial sites that have reacted to this update. All in all there are no finance / loan projects or comparable topics that were heavily affected.

Location-focused directories

From classifieds to routing there are a significant number of directories in the lists. The three winners shown below are business directories that have gained. There don’t appear to be any direct-competitor losses related to this though.

Visibility Index graphs for business registries.

Big percentage losses have been seen in a lot of lyrics and music sites. Lyrics sites have long-been a type that have seen big movements through Core Updates.

Visibility Index graphs for music and entertainment sites.

The used car segment (often very focused on finance and insurance sales, it must be said) has been hit too with some major players suffering losses. The losses do appear to be directly car-brand related and again there isn’t a small set of similar sites that have won. The gains appear to be spread across many domains.

Visibility Index graphs for car sales sites

In our analysis of losses in Germany, a potentially interesting topic has been floated. Long tail. Business, lyric and used auto searches can be in the long tail. Add locations into the mix, as with the directories and it seems that long-tail and location are the two most prevalent themes amoung the major losses and gains. The question is, has Google’s artificial intelligence found a wider range of better matches leading to the dispersal that’s being seen?

Winners and Losers – Core Update June 2021

The list of winners was created on the 10th June and shows the domain movements from the start date of the Core Update.

Google Core Update June 2021: UK Winners (Percentage, SISTRIX Data: 10/06/2021)
VI 3rd June 2021VI 10th June 2021Percentage Change

Where there are winners, there are also losers. The list below shows the largest percentage losses across some well-established domains.

Google Core Update June 2021: UK Losers (Percentage, SISTRIX Data: 10/06/2021)
VI 3rd June 2021VI 10th June 2021Percentage Change


This core update is clearly different. It’s been six months since the last Core Update and an addition to this update is expected in July.

Google appears to have a new focus with this update as the usual E-A-T sites in the medical and finance sector have not been affected as much this time round. There’s a potential focus on location and long-tail.

Google has already announced the second part of the core update for next month. And also warned directly that positive developments from this update are up for grabs. Of course, we continue to monitor the visibility on a daily basis.

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