Google Algo Updates and More – A Complete List of Changes that Could Affect Your Site’s Traffic.

googleLast updated: May 15, 2019

The following is a complete history of every Google algorithm change that was either confirmed by Google or suspected by those of us who do a lot of work helping sites that have seen traffic drops.

When I am doing traffic drop audits I am constantly referencing a number of different sources for the dates of significant changes that may affect traffic drops.  Moz has got a great list of Google Algorithm Changes, but there are many other factors that could affect a site’s traffic such as blog networks being deindexed, changes to the image algorithm, and more.  I created this list so that I would have a good reference when doing traffic drop audits.  If you can think of other changes that happened that may affect a site’s traffic, let me know!
2018 2017 2016 2015 2014 2013 2012 Early Panda Updates

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Our newsletter will keep you posted each week (every Monday) on the latest Google algorithm activity from the previous week, including real-world examples of the impacts we’re seeing with our clients and fresh insights on what may have changed with Google’s algorithms.


  • May 9, 2019 – Possibly a minor quality update. Many of our clients who have been working on E-A-T related changes saw slight increases on May 9. However a few saw slight decreases. We think that this was potentially a refresh of some sort in which Google re-assessed E-A-T signals for many sites.


  • April 27-May 1, 2019 – Likely a mild quality update. There may have been changes to how Google assesses link quality as well at this time.
  • April 26, 2019 – This was possibly a small quality update. Several sites that were previously affected by the deindexing bug that happened April 5-8 saw further drops at this time. It is unclear whether the drops are due to the bug, or an algo update.
  • April 12-19, 2019 – Google started showing more images in search on this day. According to a study done by seoClarity, there was a 10% increase in how many images Google shows for many searches starting at this time.
  • April 5-8, 2019 – This was not an algorithm update, but Google experienced a bug that caused many sites to have large number of pages drop out of the index. If traffic dropped at this time, this may be why.


  • March 18 and March 20-24, 2019 – It looks like Google is tweaking the changes made with the March 12 Core algorithm update. This is not a reversal of March 12 however. Some of our clients that saw increases on March 12 saw further increases on either March 18 or between the 20th to 24th. Some saw increases Mar 12 and a slight decrease during this turbulence.
  • March 12, 2019Significant Core Quality Update. Danny Sullivan announced that a “broad core algorithm update” was released and suggested that the answers to what were changed can be found in the Quality Raters’ Guidelines. Some have suggested “Florida 2” as a name for this update as it happened shortly after Pubcon Florida. However, this update has nothing to do with the original Florida update. Google has asked us to call this the “March Core Quality Update” rather than naming it. Early analysis shows that it has strongly affected YMYL sites. Many sites making E-A-T improvements saw beautiful changes. (Note: I am currently writing an article for Search Engine Land that will show several examples of sites that improved with this update, along with the types of changes that they made.)


  • February 27, 2019Possible small quality update. Dr. Pete from Moz noted that there was a one day increase in how many results Google was displaying on page one with some SERPS having 19 organic results. However, as that change only lasted for a day, this probably isn’t the cause. Clients of ours that saw improvements were working on E-A-T related changes. This was likely a general quality update.
  • February 23-24, 2019 – Possible small quality update. Several of our clients who have been improving their site quality saw improvements at this time. A couple of our clients who had done disavow work saw improvement. This update may have a link component to it.
  • February 16, 2019Possible small quality update. Several of our clients who have been working on quality improvements saw small positive changes at this point. We feel that this was likely a re-assessment of E-A-T for many sites.
  • February 4-7, 2019Possible small quality update. We had a couple of clients see increases after working on quality improvements, but most of our clients saw no change at this time.


  • January 31, 2019 – While this was not a suspected update date, a couple of large sites saw major drops on this date. (not .gov), and (not the official site of the DMV) saw big hits. While these could have been manual actions, as suspected by Sistrix, we think that this could reflect Google’s assessment of the “T” in E-A-T, Trust.
  • January 27, 2019 – Possible small update. This update was likely a quality update and we think there was a link component to it.
  • January 22, 2019Possible small update, quite similar to January 27. This update was likely a quality update and we think there was a link component to it.
  • January 15, 2019 – Barry Schwartz reported on a possible small update on this date. However, at MHC, we did not see much evidence of a significant update happening at this time. A few people reported that they had recovered from Medic at this time.
  • January 13, 2019 (approx) – If you are noticing a dramatic drop in impressions in GSC on or around this date, you are not alone. This is believed to be caused by the fact that GSC is now reporting data under the canonical url version. In other words, if you use utm tracking to determine when clicks are coming from Google posts, etc., those individual urls will show big drops in impressions as the data is recorded under the canonical version now.
  • January 7-9, 2019Unconfirmed update. This was probably a tweak to Google’s quality algorithms. We think that there was possibly a link component to this update as some sites that had previously had link audits done saw nice increases.
  • January 5-6, 2019 – This may have been a mild quality update. If your site saw changes in traffic at this time, be sure to note whether the changes are potentially seasonal. A lot of sites traditionally see changes at the beginning of the year. The SEMRush sensor was quite high at this time.


  • December 14-17, 2018 – This looks like a moderately significant quality update. We saw increases in a number of sites for which we had previously done site quality reviews.
  • December 4-6, 2018 – This was likely a mild quality update. We saw that several sites with previous E-A-T related hits saw further drops on this day. A few of our clients who have been working on improving quality saw slight improvements on this day. There is no obvious pattern as to what was addressed in this update. However, as some of our clients for whom we had recently filed disavows saw improvements, this could have a link component to it.


  • November 30, 2018 – The algo weather checkers all noted significant movement on this day. However, we did not see much change in our clients’ sites. Some have speculated that this was a reversal of the quality update that was seen on November 16. There seems to be more chatter in blackhat circles which means this could be either a link related update or one related to reducing the effectiveness of spam tactics.
  • November 23-26, 2018 – We saw a number of sites that had been making improvements in E-A-T that saw nice gains on this day. Although most of the algo weather checkers did not note changes, this likely was a core quality update.
  • November 16, 2018 – This was likely a mild quality update. We did see several clients have gains at this time. One had made E-A-T related improvements. Another had worked on trimming out thin quality. There is likely not one singular reason for this update, but rather, Google was likely making tweaks on their quality algorithm.
  • November 10-12, 2018 – This appears to be a significant quality update. We saw a lot of our clients that had been working on overall site quality make improvements. This update may have possibly had a link component as well.
  • November 7, 2018 – Dr. Pete noticed an increase in People Also Ask boxes in the search results. If your traffic dropped at this time, you may want to investigate whether you are possibly losing traffic due to people clicking on these results.
  • November 4-5, 2018 – This was likely a small core quality update. While we do think that it is related to the August 1/September 27 changes, most of the sites that we saw make improvements or declines on this day were not medical in nature.


  • October 31, 2018 – This appears to be a significant core quality update. Many sites that saw drops on August 1, 2018 or September 27, 2018 saw further drops on this day. We saw a couple of clients who have worked hard to improve “trust” (the “T” in E-A-T) make nice improvements.
  • October 21-24, 2018 – There was a lot of algorithmic turbulence on this day, but it is tough to pin down what changed. As most sites that were affected were also sites that saw changes Aug 1 or Sep 27, this likely was a tweak to the quality algorithms that look at trust. If you were affected, this post on the September 27 update is a good place to get recovery information. We also think that this update between October 21 and 24 could be related to links as many sites that saw changes had previous link issues. It is possible that Google is refining the way in which they determine which links to count.
  • October 15, 2018 – This date was another date on which a lot of sites saw significant changes in traffic. It does appear that there is a link component to this update. However, some sites in industries that don’t typically have link spam saw changes as well. At this point we think that this is an update in how Google assesses trust. Unnatural links can be a sign of low trust, but there are many other possible trust issues that Google looks at as well.
  • October 1-8, 2018 – There has been a lot of algorithmic turbulence this week. At this point, it looks like these may be link related changes. Almost all of the sites that we saw significant changes in were sites with link quality issues. However, this still could be further tweaks to “Medic”. Added: Danny Sullivan confirmed that they started a core algorithm update September 24 and that it would take a while to roll out. I truly believe that this update was all about trust. I think that links are one component of this update, but overall trust is important.


  • September 24-27, 2018  (and continuing into October) – Danny Sullivan from Google confirmed that this was indeed an update, but called it “small”. We saw some really significant changes in sites we monitor. Many sites who saw big gains August 1 had those gains completely clawed back. This wasn’t a complete reversal though as some sites continued to see gains/losses. This really looks like Google tweaked the Medic Update that we saw on August 1. Added: Danny Sullivan did confirm that this was a broad core quality update and that it would roll out into October. We saw most sites that were affected saw changes September 27.
  • September 17, 2018 – This appears to be a significant quality update. It is possible that this update has a link component as well. We saw nice gains for a client for whom all we had done was a link audit. But, we also saw really nice gains for clients that did not have link related issues.
  • September 8-11, 2018 – There was possibly a small update on this date. It might have been a local update. The local search forum has a good thread on it. I did not notice a whole lot of change other than a slight increase for one of our local clients. Dr. Pete from Moz originally posted that Mozcast was showing huge changes, but later said that it was a glitch. It is debatable whether there is a quality component to this update or not.
  • September 4, 2018 – Stat reported seeing more image carousels in the SERPS. This could possibly impact traffic for some sites, especially if the presence of an image carousel causes your organic positions to be pushed down the page.


  • August 22, 2018 – Barry Schwartz picked up some chatter about a possible quality update, but we did not see many changes in sites we monitor.
  • August 17/18, 2018 – This was possibly a tweak to the August 1 medic update.
  • August 7, 2018 – A large number of sites were moved over to mobile first indexing at this time. Note: John Mueller has said that when you get the message saying you’ve been moved to MFI, the move likely happened a few days before.
  • August 1, 2018 – This was a massive update likely related to E-A-T. A large number of sites selling diet or nutrition products or medical devices were hit hard. There was likely also a local component to this update as many local pack rankings changed. There are also reports of non-YMYL sites being affected as well. In my opinion, this is the biggest update we have had in a long time.


  • July 21-22, 2018 – This was a significant update. There is some speculation that this was an update to just mobile rankings. But, we also saw sites with nice gains in desktop rankings as well. This was probably a general quality update.
  • July 16, 2018 – There was possibly a mild quality update on this day. We had several clients that saw significant gains on this day. All of them had been working hard on improving overall site quality.
  • July 9, 2018 – The Speed Update started rolling out on this day. This update is designed to demote very slow pages. Slow pages can still rank well if they are by far the best result. The effect can be incremental, meaning that extremely slow pages may be demoted more strongly than moderately slow pages.
  • July 3, 2018 – A large wave of emails went out from Google to inform site owners that they had been moved to mobile first indexing. Most sites that got these emails were unsophisticated plain HTML sites. Some responsive sites got these as well. While Google is working to make it so that rankings are not hurt by MFI, it is definitely possible, especially if you have a responsive site that has different navigation on mobile vs. desktop. Note: John Mueller has said that when you get the message saying you’ve been moved to MFI, the move likely happened a few days before.


  • June 17-18, 2018 – I saw a number of sites that saw big ranking changes at this time. Many of these sites had previous link related issues. While this may have been a quality update, I think that this is more likely to be a Penguin tweak.
  • June 16, 2018Possible small quality update. Barry Schwartz reported on increased chatter. However, I did not notice much change in sites that I monitor. (However, I did notice changes on June 17 and 18 – see above.) It is possible that these changes are connected to the wave of manual actions Google recently sent out. (See the next entry.)
  • June 15, 2018 – Google sent out a wave of manual actions. It appears that these actions targeted sites using PBN’s and blackhat paid links. If your site saw changes at this time, it could be that Google devalued part of your link profile, or that competitors were affected.
  • June 8, 2018 – I did not notice a big change in any sites that I monitor, but Barry Schwartz noticed an uptick in forum chatter around this day. Also, there are quite a few comments on his blog post from people who saw significant losses. This was likely a mild quality update.
  • June 4, 2018 – There was possibly a mild quality update on this day.


  • May 25, 2018 – GDPR went into effect on this day. If you are working with a site that has shut off traffic from European citizens this may affect traffic values starting on this day.
  • May 22-24, 2018 – This looks like a significant update. Many sites that were affected had seen changes with previous quality updates. There was significant chatter in the blackhat forums on this update. Also, we have one client with big drops. As this site had been involved in link buying (not on our advice!) for a while, we are suspicious that this update may have a link component to it.
  • May 17-18, 2018 – Quite a few sites were affected by this quality update. Most sites that I saw affected by this update were previously affected by a significant quality update, such as the one on April 30, 2018.
  • May 14, 2018 – This looks like a mild quality update.
  • May 7-8, 2018 – This is shaping up to be a significant overall site quality update.


  • April 30, 2018 – Significant core quality update. Many sites that saw increases or decreases were ones that were affected by either the April 16, 2018 update or the March 9, 2018 update.
  • April 29, 2018 (approx) – There was a bug in Google image search which caused many images to appear as blank rectangles. Although this is not technically an algorithm update, it’s something that could cause changes in search traffic for sites that receive a lot of traffic from image search.
  • Aprl 23, 2018This was not an announced update, but we saw a lot of sites have either positive or negative movement on this day. Some of our clients who have been working a lot on improving site quality saw gains at this time.
  • April 16, 2018Announced core algorithm update. A lot of sites that saw movement on this day were sites that also were affected in the March 7-9 update. We also saw clients of ours that have been working on improving E-A-T see nice improvements as well.


  • March 28, 2018 – Possible mild quality update.
  • March 23, 2018 – This is shaping up to be a big update. It is confusing as well because also did updates to their database at this time. The SEMRush update was one in which they cleared out a lot of “old” or unrelated keywords. As such, many sites that see a drop in SEMRush are not seeing a corresponding drop in analytics. BUT…there are quite a few sites that I have seen that did indeed see drops or gains at this time. This looks like a general quality update, but I will report more on this in my next newsletter.
  • March 14, 2018 – There was more algorithmic turbulence on this day. Most sites that saw increases or decreases on this day were previously affected on either March 3 or 9.
  • March 7-9, 2018 – This update was a big quality update, that was confirmed by Google. The March 9, 2018 Google update was one that benefitted sites that had been working on overall site quality. We saw many clients that saw beautiful improvements. If you were negatively affected by this update, it is not because you have been demoted, but rather, competitors have been promoted above you. Google confirmed that this update started rolling out on March 7, 2018. While a few sites saw changes March 8, the majority of sites that were affected saw their big changes on March 9.
  • March 3/4, 2018 – This may have been a mild quality update. This is the start of a bunch of algorithmic turbulence in March.


  • February 20, 2018 – This looks like a moderately significant quality update.
  • February 15, 2018Changes to Google image pages. Google made changes to their image pages so that it is harder for people to view an image from the search results. This could result in more clicks to a website as Google’s new interface is encouraging people to visit the site on which the image is hosted.
  • February 3, 2018 – There was a reduction in the number of featured snippets that Google is showing. If your site lost traffic starting on this day, it may be worthwhile to check and see if the number of featured snippets have dropped. (Note: If you are a SEMRush or Ahrefs subscriber, these counts should be available to you there.)


  • January 28/29, 2018 – Possible mild quality update. I have not seen any obvious changes on sites I monitor. In the comments section of this article you’ll see that one user thinks that big pharma sites were hit. If I get more updates on this, I’ll let you know.
  • January  15, 2018 – Possible mild quality update.



  • December 26, 2017 – This appears to be a significant quality update. However, it is hard to judge this as many sites naturally see seasonal increases or decreases at this time. In my newsletter, I give some examples of clients of ours that saw nice gains in conjunction with this December 26 update. They were all clients that have been working hard on improving site quality.
  • December 25, 2017 – A large number of manual actions were given out on this day.  Many of the sites that were hit relied heavily on PBN links or scholarship links.
  • December 18, 2017Possible quality update.
  • December 15, 2017 – Many celebrity websites were hit algorithmically on this day so that they no longer ranked well for their name. Really though, in most cases the site did not deserve to rank well. This may have been a tweak to the effectiveness of exact match domains.
  • December 12, 2017 – This appears to be a significant algorithm update. Barry Schwartz dubbed it the “Maccabees update” as it happened during Hanukkah. We have noticed that many sites that were hit were sites that were hit with quality updates. I do think that a big part of this update dealt with analysis of E-A-T (Experience, Authoritativeness and Trust.)
  • December 5, 2017 – Possible quality update.


  • November 27, 2017 – This change was not written about much or discussed much in the search community, but several of our clients saw increases or decreases that started this day. This was likely a mild quality update.
  • November 15, 2017 – Possible quality update. I did not see much change in the sites that I monitor, but most of the algo flux tools showed a big increase. Algoroo noted this as the most fluctuation in the SERPS since December of 2016. I do not think that this is related to the Firefox default search engine change (see below) as the algo flux tools check rankings, not traffic.
  • November 14, 2017 – Firefox changed their default search engine back from Yahoo to Google. If your site performs better on Yahoo than Google, you may see a drop that coincides with this date. Keep in mind that as users update their Firefox version, this could cause changes on other dates as well.


  • October 28-30, 2017 – This appears to be a significant quality update. I saw several sites affected either positively or negatively that were previously affected on the dates of other significant quality updates.
  • October 12, 2017 – Although I didn’t notice significant changes on this date, Glenn Gabe did. This was likely a small quality update.
  • October 8, 2017 (and possibly Oct 6-9) – This was a relatively big algo change. I saw several sites that saw improvements after making changes in their E-A-T (Experience, Authority and Trust) which is something that is prominent in the Quality Raters Guidelines.
  • October 4, 2017 – While I didn’t notice significant changes on this date, Glenn Gabe did. This may have been a quality update.


  • September 27, 2017 – There was significant chatter about an update at this time. More info to follow as we get more information to review. I’m wondering if this is related to Apple’s switch to Google from Bing (see the next entry).
  • September 25, 2017 – Apple started using Google rather than Bing as their default engine for Siri. This could potentially cause an increase or decrease depending on how Bing/Google dependant your site is. For example, sites that rank well on Bing, but not on Google likely will see a decrease.
  • September 19, 2017 (Approx) – This seems to be a significant quality update. I saw a number of sites that saw improvements at this time after working hard to clean up quality issues.
  • September 6 & September 8, 2017 – Small unannounced quality update. I had one client who previously saw nice improvements on March 8 (Fred) who saw further improvements on September 8. There are examples of a few more recoveries here.
  • Early September 2017 – Google made a change in that they appear to be preferring AMP results in featured snippets on mobile. If you have lost traffic from featured snippets, this could explain why.


  • August 19-22, 2017 – Moderately large quality update – . This was an unannounced update. I saw several sites on this day that saw drops. Each of them were sites that look dated, have technical issues and are not kept up to date. While there could be other issues, I feel that this change has to do with technical quality and freshness.
  • August 7, 2017 – There was some kind of significant update on this day. So far, it looks like this is a link related algorithm. I saw a couple of clients who saw nice Penguin recoveries in the fall of 2016 who had further improvements on Aug 7. See screenshots here.


  • July 26, 2017 – There was a significant change in rankings on this day that was noticed by most of the SERP tracking tools. I personally saw increases in some sites that previously had Penguin recoveries. As such, I think this may have been a tweak to the Penguin algorithm. But, it could have also been core quality as well. I’ll update this if I get more info.
  • July 9, 2017 – There appears to be a core quality update on this day. A few people said that they saw reversals of changes that happened on June 26, 2017. Others who saw increases on June 26 saw no change on July 9. It sounds to me like this is a tweak to the way in which Google assesses site quality. It’s hard to point out any specifics though.


  • June 26, 2017 – There was a significant algorithm update on this day. It appears to be related to overall site quality.
  • June 19, 2017 – This change wasn’t talked about much, but I saw several spammy sites that saw big drops on this day.
  • June 14, 2017 – Barry Schwartz reported a small update that seemed significant enough to report on. However, not many changes were seen around the web.
  • June 13, 2017 – (Date approximate). There was a big change in the local search algorithm. According to local search expert, Joy Hawkins, several changes happened around this time. Some businesses without websites started to appear in the 3-pack, the proximity to the searcher was given more relevance, and also, it is possible that reviews were given less weight in the algorithm.


  • May 17, 2017 – Unannounced significant algorithm change. It’s unclear whether this was an actual ranking shift, or whether changes in featured snippets are responsible for these changes. Glenn Gabe is seeing reversals of sites that were affected by recent quality updates and also sites that were affected that did not have featured snippet changes. This looks like another core quality algorithm update. There are good thoughts by Glenn Gabe on this update here and there is more followup from Barry Schwartz here.
  • May 4, 2017 – Lots of sites with previous changes on quality update days saw changes on this day as well.


  • April 26, 2017 – This was not written about widely, but I saw a number of sites with previous Panda issues have ups or downs on this day.
  • April 17/18, 2017 – Unannounced core algorithm update. This change appears to have affected a lot of sites.
  • April 4, 2017 – Mild algorithm turbulence.


  • March 14, 2017 – Owl Update.  This update is geared towards removing offensive results from autosuggest and featured snippets.
  • March 7-8, 2017 – Fred update. This was a major quality update. It appears to have affected sites that existed primarily for SEO reasons. I also think that at this time Google tweaked the algorithm to reward sites with good E-A-T (Experience, Authority and Trust).


  • February 7, 2017  – Large core algorithm update . This update affected a lot of sites. I saw several sites that I think dropped in rankings because of a lack of E-A-T (Experience, Authority and Trust).
  • February 3, 2017 – New algorithm to devalue spammy sites in Japan.
  • February 1, 2017 – Large algorithm update that appears to be related to links. This may have been a tweak to the Penguin algorithm. Some suspected that Google became better able to find and devalue links from PBNs (private blog networks) at this time.




  • November 18, 2016 – Significant core algorithm update. May have been a reversal of the Nov 10 update.
  • November 10, 2016 – Significant core algorithm update. Glenn Gabe was suspicious that this could have been a test of the mobile first index. However, I have seen a number of sites that were hit on this day that had on-site quality issues.


  • October 5, 2016 – This was probably a tweak to the Penguin algorithm. Some sites that I monitor that saw improvements with Penguin 4.0 saw further improvements on this date. Also, many sites with link issues lost traffic starting this day. I think that this is probably not because Penguin penalized the sites, but rather, because Penguin devalued links that were previously helping.


  • September 23, 2016 Penguin 4.0. This was a huge update to Penguin. Now, Penguin no longer demotes sites, but rather, the algorithm simply devalues unnatural links that are pointing to your site.
  • September 15, 2016 – Significant unannounced update. Some thought this might be a test of Penguin, but it appears to be quality related.
  • September 2, 2016 – Significant core algorithm update.








  • February 18, 2016 – Google changed the SERP layout to now include four paid ads at the top of the results for many searches and none on the side. This could possibly result in a lower click through rate for some sites that have high organic rankings.
  • February 9, 2016 – Possible changes in the mobile algorithm. Accuranker noted huge fluctuations in mobile rankings. However, not much was reported amongst site owners. Dr. Pete from Moz noted that these changes may be due to more deep linking for Android Apps in the SERPS.
  • February 5, 2016Possible changes in the mobile algorithm. Dr. Pete from Moz noticed a big jump in the number of sites that had the “mobile friendly” tag appearing on the first page of mobile results. Other ranking tools picked this up as well. However, there was not much chatter amongst webmasters. Plus, it appears that this change reverted the next day. This may have been some type of test of a new mobile algorithm change. Dr. Pete from Moz noted that these changes may be due to more deep linking for Android Apps in the SERPS.
  • February 5, 2016 – Google has penalized a large Japanese link network. If you had backlinks coming from this network then you likely saw a drop in rankings.


  • January 17, 2016 – SEOs reported seeing a LOT of changes in the SERPS once again. Google confirmed that this was not Penguin, but rather, more changes to Google’s core algorithm.
  • January 8-10, 2016 (approx) – Changes to Google’s core algorithm. There was no name for this update as Google said it was just one of the many changes they make to their core algorithm all year. However, many webmasters noticed significant changes in rankings at this time. There were quite a few who were convinced this was a Penguin update, but I personally was not seeing any changes on Penguin hit sites that I monitor. Others were thinking this could be Panda. But ultimately it was an overall change to the core algorithm. At this point there is no specific advice for recovery other than to continue to improve the overall quality of your site.


  • December 17, 2015  – Google announced that they will be indexing https by default from now on.
  • December 16, 2015 – Possible Quality/Phantom tremor. (Note – These “algo changes” are hard to pinpoint. These dates are ones on which a lot of people reported significant changes in rankings. Glenn Gabe noted that many sites that saw ranking changes were ones that were also affected by Google’s Quality (Phantom) Update. Instead of naming these “Possible Quality/Phantom tremors” I could also call them, “unknown algorithm changes”.
  • December 14, 2015 – You may notice an “update” label in Google Search Console Analytics data. This does not actually represent a Google update, but rather a change in the way that Google displays impressions and clicks for websites and apps.
  • December 12, 2015 – Possible Quality/Phantom tremor.
  • December 10, 2015 – Possible Quality/Phantom tremor.
  • December 4, 2015 – Possible Quality/Phantom tremor.


  • November 28, 2015 – Possible Quality/Phantom tremor.
  • November 19, 2015 – Possibly an update to the Quality/Phantom algorithm. Many webmasters noticed ranking changes at this time although it is not obvious whether this was a Panda related change. Glenn Gabe noticed that many sites with quality issues were affected.
  • November 2, 2015 – Possible Panda tremor. I personally saw several sites with Panda issues either increase or decrease on this date. However, other SEOs who do Panda work did not notice changes. This “new Panda” may make it difficult to determine when Panda related changes are happening.
  • November 1, 2015 – Google’s app interstitial penalty goes live. Mobile friendly pages that show a large interstitial app will no longer get the mobile friendly label. This could cause a drop in mobile traffic.


  • October 14/15, 2015 Possible Panda movement – Some wondered if they were seeing more “zombie” traffic being reported. (Zombie traffic is useless non-legitimate traffic that Google can occasionally send). However, several sites reported Panda improvements or hits on this date. Still, many sites that are awaiting Panda recovery have not seen any movement at all.
  • October 7, 2015 (approx)Possible unannounced algo shift. While nothing official was announced on this day, many webmasters saw a change in rankings. Some speculated that this was Google testing Penguin. Others thought it was a continuation of the long rollout of Panda that started in July. Personally, I saw some small increases in a couple of sites that had both Penguin and Panda issues.
  • October 5, 2015 (approx) – Google announced that they have released a new algorithm to deal with how they display hacked sites in the search engine results. This change affects 5% of queries, which is a fairly big thing. If you noticed a drop on or around this date, you may want to investigate for evidence of hacking. (Quick tip…try doing Google searches like this – viagra | cialis | ugg | kors to see if there are pages on your site that are hosting hacked content.
  • October 1-14 (approx) – Do you run a Wix website? For some reason Google has had trouble crawling these and they have been dropping out of Google’s index. Google became aware of the problem around October 13 and is working to fix it. This change also affected other websites that use AJAX crawling with an escaped fragment.


  • September 16, 2015Possible Panda tremor. Glenn Gabe noticed several sites seeing significant Panda hits/recoveries on this date. Still, most sites awaiting Panda recovery saw nothing.
  • September 16, 2015 (approx) – iOS 9 was released along with a feature to allow users to block ads. It appears that this feature also blocks scripts that track analytics. If you see a drop in Google Analytics traffic around this time, compare your mobile traffic to desktop to see if there is a big difference. It may be that you’re not actually seeing a traffic drop, but that visits from iPhones and iPads are no longer being tracked.
  • September 15, 2015 Google image referral bug – This bug affected images outside of the US. Sites that see a lot of referrals from Google images may have a temporary drop on this day. It was fixed as of September 16.
  • September 9, 2015Possible Panda tremor. I didn’t personally see much Panda action on this day, but Glenn Gabe noticed some sites seeing Panda related movement.
  • September 2, 2015 – Possible Panda tremor.


  • August 31, 2015Possible Panda action – Panda 4.2 started rolling out in mid July but very few people reported changes. Around August 31, a few sites noticed some Panda related movement. For example, which had seen an increase in July saw a slight decrease on August 31. Still, most SEOs who work with Panda hit sites saw very little movement on either of these dates.
  • August 6, 2015 – There were big changes in how Google displays local listings. It appears that in most places where Google would previously display 7 local listings, they are now only displaying 3. This is not just a US change, but appears to be international. While some sites will see a drop in traffic because they were previously in the lower half of the 7-pack, others may see an increase in traffic because Google is no longer displaying the full address which may cause more people to click through to the website.
  • August 1, 2015 (approximate date)Unannounced algo update. Many people saw dramatic changes in rankings. I had several Penguin hit clients who saw significant improvements at this time, but Gary Illyes from Google told me that this was not Penguin related. It appears that most people who saw changes at this time had those changes revert a few days later.





  • Last week of April: Possible changes to the Google news algorithm.
  • April 29, 2015 – May 1, 2015  – The Quality Update, also known as Phantom 2. This was a fairly large update, which was quite similar to Panda. The focus appears to be on on-site quality, but Google has not given much instruction on recovery other than a vague, “Improve your quality”.
  • April 25, 2015 (date approximate) – Possible unannounced algorithm change. Many people saw ranking changes and the tools like Mozcast and Algoroo reported changes that appeared to be unrelated to the mobile friendly algorithm.
  • April 22, 2015 (or possibly starting within the following week) – The mobile friendly algorithm was launched. This algorithm gives a boost to sites that Google deems mobile friendly. It only affects mobile rankings and not desktop.
  • Sometime in April (probably): Google likely launched a change to the doorway page algorithm that punished sites with doorway pages. However, no one in the SEO world really noticed much change so it’s hard to say exactly when this happened.


  • March 25, 2015 – Possible unannounced algorithm change. Some people suspected that this was a test of Panda. John Mueller from Google commented that these changes and those seen around March 18-20 were likely just normal algorithm fluctuations.
  • March 18-20, 2015 (dates approximate) – Possible unannounced algorithm change. Many people saw ranking changes, but this was not Panda or Penguin.
  • March 10, 2015 – Google know showing drink recipes in the knowledge snippets. This might affect some recipe sites.


  • February 19, 2015 – A bug causes “This site may be hacked” messages to appear for a large number of sites, resulting in massive temporary traffic drops.
  • February 4, 2015 – Possible unannounced algorithm update. This was not Panda or Penguin. Glenn Gabe noticed that many of the sites that were affected by this change had quality issues, however.
  • February 4, 2015 – Google launched a mortgage calculator. This won’t affect traffic for most sites.



  • December 22, 2014 (+ a few days for rollout) – The Pigeon Algorithm, affecting the local search results rolled out to English speaking countries outside of the US such as Canada, Australia and the UK.
  • December 5-6, 2014Penguin fluctuations.
  • December 2, 2014 – Possible Penguin refresh. This was likely a continuation of Penguin 3.0 that started on October 17. Many sites saw further hits or increases on December 2, but most of these appeared to be short lived.


  • November 27, 2014 – Confirmed refresh of Penguin. This was a continuation of Penguin 3.0 that started on October 17. This was also Thanksgiving weekend, so changes in traffic around this time can be difficult to interpret.
  • November 24, 2014 – A large Polish link network was taken down by Google.
  • November 14, 2014Google drops the carousel for local results. This likely didn’t result in much traffic fluctuation, but could possibly have caused some changes for some small businesses.
  • November 13, 2014 – Possible unannounced algo update. There is a possibility that this was a mild refresh of Penguin. However, I did not see much change in sites I monitor.
  • November 10-11, 2014 – Possible unannounced algo update. This likely was not Panda or Penguin, but many people saw ranking changes.


  • October 24, 2014 – Unannounced Panda refresh. This was not announced by Google but most of us who do Panda work noticed dramatic changes in some Panda hit sites at this time. 6 months later when we were wondering why Panda was no longer refreshing, John Mueller confirmed that the last refresh was at the end of October.
  • October 22, 2014Possible tweaking of the Penguin algorithm.
  • October 21, 2014Google Pirate Update – Aimed at illegal torrent sites and other sites with large amounts of pirated content.
  • October 17, 2014 – Penguin 3.0 refresh. After waiting for an entire year, Penguin finally refreshed on this date. This was not an Update but rather a refresh which means that nothing changed in how Google makes Penguin calculations, but they just re-ran the algorithm. This was a rolling algorithm refresh that had no fixed end. However, most sites that saw changes saw them on October 17-18, October 22, November 27, December 2, 5 or 6. This was supposed to be a refresh that would allow people who had done cleanup work to recover, but many sites that should have recovered, did not.
  • October 9, 2014Possible testing of the Penguin algorithm. This is not confirmed, but I had many people who had sites previously affected by Penguin contact me to say that rankings were up. In most cases these disappeared within 24 hours. If you saw a short spike in traffic on this day it may be that your rankings were part of Google’s testing on Penguin.
  • October 12, 2014Probable Panda Tremor – Many sites that were previously affected by Panda 4.1 in late September saw an increase or decrease in traffic at this time.
  • October 4-6, 2014 (dates approximate) – Possible unannounced update – Many people saw dramatic changes in rankings at this time. Most likely this was a continuation of the slow rollout of Panda.


  • September 29, 2014 – Possible Panda Tremor – People who do a lot of work with Panda sites saw a lot of up and down movement on sites on this day. Some had seen no movement with the initial rollout of Panda 4.1 on September 25.
  • September 25, 2014 (and continuing off and on for 1-2 weeks) – Panda 4.1. This was a slow rollout that apparently took a week or more and may have started a few days prior to September 25.
  • September 21-23, 2014 (dates approximate) – Google gives out many manual penalties to private blog network sites. If you used PBN links to rank, you may have seen a drop at this time.
  • September 16, 2014Google penalizes several Turkish news sites. This is not likely to affect most sites’ traffic.
  • September 5, 2014Probable unannounced Panda refresh. Google did not announce a refresh of Panda on this date, but many people who do work with Panda hit sites noticed significant changes.




  • June 28, 2014 – Possible Unannounced Update – May have been due to a drop in Authorship photos.
  • June 24, 2014Possible Mild Unannounced Update – I debated even including this one as not many sites appeared to be affected but it is possible that Google made some significant algorithmic changes on this date.
  • June 21, 2014Possible Mild Unannounced Update – The tools that track changes in the SERPS all noticed something was going on, but there was not a lot of chatter on search engine forums about changes.
  • June 12, 2014Payday Loans 3 – This update to the Payday Loans algorithm now targets spammy queries as well as spammy sites.


  • May 28, 2014 (approx)Possible unannounced update. Many people thought that this was a Penguin refresh, but Google denied it. Personally, I do not think that this was related to Penguin.
  • May 20, 2014Panda 4.0  – This was a large Panda update that affected many sites. Quite a few sites that were previously hit by Panda saw very dramatic increases in traffic. This was a whole new version of Panda with a new architecture that was apparently much more lenient. My note: Many sites that saw changes with Panda 4.0 started to see changes a few days before the official announcement of Panda 4.0.
  • May 16, 2014 (approx)Payday Loans 2 – Google made the announcement on May 20 that they had released a new version of this spam algorithm that targets spam in competitive niches. You don’t have to be a Payday Loans site to be affected. This caused a lot of confusion as Payday Loans was updated a couple of days before a massive Panda update (Panda 4.0).
  • May 2 & May 7, 2014Possible unannounced update. However, this seemed to revert on May 12. Many big brands saw rankings change around this time.







  • November 27-29, 2013 (dates approximate) – Possible unannounced update. Barry Schwartz reported that a lot of sites were reporting traffic losses, but it was possible that this was just low traffic due to the Thanksgiving holiday.
  • November 14, 2013Unannounced update – Google did not announce an update, but a LOT of websites had their traffic adversely affected on this day.
  • November 1-5, 2013 (dates approximate) – Possible unannounced update.


  • October 16, 2013 – Possible unannounced update.  It was speculated that this was related to Penguin, but we have no confirmation of this.
  • October 4, 2013Penguin 2.1 update – This Penguin update affected a lot of sites.



  • August 20, 2013Unannounced update – May have been Hummingbird
  • August 6, 2013 – Google announces In Depth Articles.  This likely did not have a drastic effect on the traffic of most sites.  But, if you notice a change on this date, it may be that some of your articles were either pushed up or down in the SERPS depending on whether Google thought they were worthy of the “In Depth Article” label.
  • August 1, 2013Google Analytics Reporting bug – For many, but not all Google analytics users, GA just stopped reporting traffic.  I’m not sure if this has been corrected or not.  But, if you see a sharp dip on Aug 1, it’s probably just a reporting error.


  • July 26-29, 2013 (dates approximate) – Possible Unannounced update.  The general consensus was that this probably was not a Panda or Penguin update.  It is even debatable whether anything actually happened.
  • July 19, 2013 – The Knowledge Graph expanded significantly.
  • July 12-18, 2013 (dates approximate)- Confirmed Panda update. This was the first of the new “softer” Panda updates.


  • June 27, 2013 (and surrounding dates) – “Multi-Week” Algorithm update. There were many ranking fluctuations during the last week in June.
  • June 19, 2013 – Possible unannounced update.  However, if you read the comments, many people thought this was a Google Analytics bug.
  • June 14, 2013 – Google changes the image carousel in image search. This *might* affect image search queries.
  • June 11, 2013Payday Loans algorithm rolls out.  This algorithm doesn’t just affect payday loans sites, but any site that has the potential for super spammy SERPS.
  • June 5, 2013Unannounced update
  • June 5, 2013Knowledge Graph adds nutrition info.  This won’t affect most sites, but certainly can cause a drop in rankings for calorie counting/fitness/recipe sites.



  • April 6, 2013Potential unannounced update – Although, if you read the comments, it sounds like perhaps there was a temporary glitch with Google analytics


  • March 27, 2013Google Updates its Quality Guidelines for News – “If a site mixes news content with affiliate, promotional, advertorial, or marketing materials (for your company or another party), we strongly recommend that you separate non-news content on a different host or directory, block it from being crawled with robots.txt, or create a Google News Sitemap for your news articles only. Otherwise, if we learn of promotional content mixed with news content, we may exclude your entire publication from Google News.”
  • March 15, 2013Google announces no more regular Panda updates – From this point on, Google will no longer be announcing Panda updates.  They will gradually roll out with the regular algorithm changes.
  • March 14, 2013 Panda Refresh? – Google said that they would release Panda this weekend.  No official date was given, but most SEO’s believe it was around March 14…possibly March 13.
  • March 7, 2013Google Penalizes SAPE links – A Russian link network, SAPE links is penalized so that links coming from this network are likely worthless.


  • February 22, 2013News Websites Penalized – Google reduced the PageRank of many UK news websites to zero because they have been selling links in the form of advertorials



  • December 21, 2012 Panda Refresh
  • December 13, 2012Safe Search Changes – Google updated the way that Safe Search works so that it is now more strict on explicit content.
  • December 10, 2012Unannounced update? – No official update was announced, but many webmasters were compaining about traffic changes at this time.
  • December 4, 2012 – Google expands the Knowledge graph.




  • September 28, 2012EMD update – This update demoted low quality exact match domains.
  • September 27, 2012Panda update – This was a major update that affected a lot of sites.
  • September 18, 2012Panda refresh
  • September 14, 2012Diversification update – This was a small update intended to diversify search results.







Earlier Panda refreshes/updates:

  • February 27, 2012
  • January 18, 2012
  • November 18, 2011
  • September 28, 2011
  • August 12, 2011
  • July 23, 2011
  • June 21, 2011
  • May 9, 2011
  • April 11, 2011
  • February 23, 2011(initial rollout of Panda)


Did I miss any important algo shifts?  Please let me know and I’ll give you credit as it is added to the list.

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Marie Haynes is the founder of HIS Web Marketing, formerly at In 2015, she rebranded the company to Marie Haynes Consulting Inc.
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