Until June 2019, site owners usually learned about a Google core update the same way: rankings moved, forums lit up, and Google confirmed it afterwards, if at all. On 2 June 2019 that changed. Google announced a broad core update the day before it went live, the first time it had pre-announced a core update.
The June 2019 Core Update rolled out from 3 June over about five days. Part-way through, Google also launched an unrelated change to how many results from the same site can appear for a query, later known as the site diversity system. Two changes in one week made analysis harder, and the episode is still a good lesson in separating overlapping updates.
This article covers the pre-announcement, the rollout, the sectors trackers reported as affected, and how the site diversity change fits in.
Key Takeaways
- Google pre-announced the June 2019 Core Update on 2 June 2019; it went live on 3 June. This was the first pre-announced core update.
- The rollout took about five days.
- Trackers reported broader effects than earlier updates, with visibility gains for some medical sites.
- A separate site diversity change launched during the rollout, generally limiting results to two listings per site.
- Google said the two changes were unrelated, so analyse them separately.
The June 2019 updates at a glance
| Item | June 2019 Core Update | Site diversity change |
|---|---|---|
| Announced | 2 June 2019 (pre-announced) | During the core update rollout |
| Live | 3 June 2019 | Early June 2019 (our fact base dates it to 6 June) |
| Rollout | About five days | Not specified in the sources we reviewed |
| Type | Broad core update | Ranking system for result diversity |
| Confirmed by Google? | Yes | Yes |
| What it does | Broad changes to ranking systems; no specific target | Generally no more than two listings from the same site in top results; subdomains usually treated as part of the root domain |
| Still active? | Superseded by later core updates | Yes, listed as the site diversity system in Google's ranking systems guide |
Why Google pre-announced it
According to Search Engine Land, the search community had asked Google to be more proactive about core updates. Google's Search Liaison, Danny Sullivan, said there was nothing specifically "big" about this update, and that Google wanted to avoid site owners and SEOs being left "scratching their heads after-the-fact". Google said it would tweet again when the update went live.
The pre-announcement did not include any new advice. Google pointed back to its existing guidance:
“There's no 'fix' for pages that may perform less well other than to remain focused on building great content.”
— Google, quoted by Search Engine Land, Google pre-announces June 2019 core search algorithm update
Pre-announcements became more common after this. Today, Google usually posts core updates on its Search Status Dashboard when they start and when they finish. Our guide to how Google rolls out core updates explains the process, and what to do during a core update rollout covers the practical side.
Which sectors were affected?
Google did not say which sectors would be affected, and it never does for core updates. The reports below come from third-party tools, summarised in Search Engine Land's review of 2019 updates.
| Source | What it reported | Type of evidence |
|---|---|---|
| Sistrix and RankRanger | The range of affected domains was broader than in earlier updates | Visibility and rank tracking data |
| SearchMetrics and Moz | Visibility gains for medical sites | Visibility data |
| Moz (site diversity) | Small overall impact from the diversity change | Tracking data |
| SearchMetrics (site diversity) | Keywords returning three URLs from one domain fell from 6.7% to 3.5% of the time | Tracking data |
| Sistrix (later, September 2019) | The Daily Mail recovered in September after being hit in June | Visibility data, single example |
The gains for some medical sites drew attention because many health publishers had reported losses after the August 2018 "Medic" update. It is tempting to read June 2019 as a partial reversal, but Google did not say so. A more cautious reading is that core updates re-evaluate content continuously, so sites that improved, or whose competitors changed, could move in either direction.
The site diversity change
During the core update rollout, Google launched a change to reduce cases where a single site dominated the results for a query. Google's ranking systems guide still describes it today:
“we generally won't show more than two web page listings from the same site in our top results”
— Google Search Central, A guide to Google Search ranking systems
Search Engine Land's summary adds a few details: subdomains are generally treated as part of the root domain, the change applies to the main results rather than features such as Top Stories or video results, and Google may still show more than two results from one site when it is especially relevant. Our explainer on the site diversity system covers how it works now.
How to separate overlapping updates
When two changes land in the same week, it is easy to blame the wrong one. A simple process helps:
- Note the exact dates of each change and wait until both have finished rolling out.
- Check whether your losses are on queries where you previously had three or more results; if so, site diversity may explain them.
- Check whether a different URL from your site now ranks in place of the one you lost (consolidation rather than loss).
- Look for broader quality patterns, such as whole sections or page types falling, which point more towards the core update.
- Review the pages that gained for your queries and compare their usefulness with yours.
- Make improvements based on what you find, and keep tracking through the next core update.
Our guide to analysing overlapping Google updates walks through this in more detail.
Common mistakes
- Blaming the core update for diversity losses. If you lost a third or fourth listing for a query, that is a different change.
- Splitting content onto subdomains to get more listings. Google generally treats subdomains as part of the root domain for diversity.
- Assuming pre-announcement means a big update. Google said nothing about this update was specifically "big".
- Reading sector gains as a policy. Medical site gains were observations, not a Google statement.
- Making changes before the rollout ends. Wait for stable data before deciding what to fix.
Where June 2019 fits in the timeline
June 2019 sat between the March 2019 core update, the first month-named one, and the September 2019 core update, which trackers described as weaker than June. In August 2019, between them, Google published fuller guidance on core updates. For the full sequence, see our Google core updates guide and the algorithm updates hub.
Related Guides
- Google's September 2019 Core Update Explained
- Google BERT Update (2019): How Language Understanding Changed Search
- Featured Snippet Deduplication (2020): Why Snippet Pages Lost Their Second Listing
Frequently Asked Questions
When was the June 2019 core update?
Google pre-announced it on 2 June 2019 and it went live on 3 June, taking about five days to roll out.
Was it the first pre-announced core update?
Yes. Search Engine Land's review of 2019 describes it as the first time Google pre-announced a core update.
Which industries were affected?
Google did not say. Tools reported broader effects than earlier updates, and SearchMetrics and Moz saw visibility gains for medical sites.
Is the site diversity change part of the core update?
No. It launched during the core update rollout but was a separate change. It is still listed as the site diversity system in Google's ranking systems guide.
Can a site still get more than two results for a query?
Yes, sometimes. Google says it generally won't show more than two listings from the same site in top results, but it may show more when especially relevant.
Conclusion
The June 2019 Core Update changed how Google communicates more than how it ranks: advance notice became the norm. Its overlap with the site diversity change is a useful reminder to check dates carefully and separate causes before acting. If you need help untangling a drop, see our ranking drop recovery guide or ask our SEO team to review your data. You can request a quote any time.
References
- Google pre-announces June 2019 core search algorithm update - Search Engine Land
- The big list of 2019 Google Search algorithm updates - Search Engine Land
- A guide to Google Search ranking systems - Google Search Central
- Google Sept. 2019 Core Update 'weaker' than June core update - Search Engine Land
- Google Search's core updates and your website - Google Search Central
