A site owner once asked me, "I already cleaned up my links after Penguin 2.0. Why did I get hit again in October?" It is a fair question, and it gets to the heart of how Penguin worked in 2013. Cleaning up was not a one-time job. Every Penguin run looked at your links again, with fresh data, and judged you on whatever it found.
Penguin 2.1 launched on Friday 4 October 2013. Matt Cutts said it noticeably affected about 1% of searches. That made it one of the larger Penguin releases, bigger than any refresh before it. Then Penguin went quiet for a full year.
In this post I will explain what Penguin 2.1 was, what Google confirmed, what was only reported, why the year-long wait afterwards hurt so many businesses, and what the recovery lessons still teach in 2026. You can see where it sits among other 2013 changes on our Google algorithm updates timeline.
Penguin 2.1 at a glance
| Item | Details |
|---|---|
| Date | Friday 4 October 2013 |
| Type | Data refresh of the Penguin 2.0 algorithm (no new algorithm announced) |
| Confirmed by Google? | Yes, by Matt Cutts on Twitter |
| Scale | About 1% of searches "to a noticeable degree" |
| What it targeted | Link spam: manipulative links and the sites that relied on them |
| Who was affected | Not documented by Google; reports described sites newly hit and sites hit again after 2.0 |
| Google's internal count | Fifth Penguin release, so some coverage called it "Penguin 5" |
| Next Penguin run | Penguin 3.0, 17 October 2014, about a year later |
Where Penguin stood after 2.0
To understand 2.1, you need to know what came just before it. On 22 May 2013, Google launched Penguin 2.0. In his post "Penguin 2.0 rolled out today", Matt Cutts described it as "the next generation of the Penguin webspam algorithm" and said "about 2.3% of English-US queries are affected to the degree that a regular user might notice." He also stressed it was "an updated algorithm (not just a data refresh)."
Penguin 2.0 was widely reported to look deeper into sites than the first version, beyond the homepage to inner pages. Google never published the details, so I treat that as the industry's reading, not a confirmed mechanism. I cover that release fully in my post on Penguin 2.0 and deeper link spam detection.
So in October 2013 the situation was this: Google had a newer, stronger Penguin engine, and it had run it only once. Penguin 2.1 was the second run of that engine on new data.
The launch and Matt Cutts' tweet
Barry Schwartz at Search Engine Roundtable said he had noticed "signs of this around 9am EDT" that Friday, but did not have enough chatter to write it up. Later that day Matt Cutts confirmed it on Twitter:
“Penguin 2.1 launching today. Affects ~1% of searches to a noticeable degree.”
— Matt Cutts, quoted by Search Engine Roundtable, report on the Penguin 2.1 launch
A few things stand out from the launch:
- It was a "late Friday release," as Schwartz called it, so most site owners discovered the damage over the weekend or on Monday morning.
- Google gave no explanation beyond the tweet. Search Engine Journal's Penguin history notes there was no official write-up for this refresh.
- Early numbers looked big. Schwartz described the early stats he saw from affected sites as "huge," though he did not publish them.
- The naming was messy again. Google counted it as the fifth Penguin release, per Wikipedia's Google Search timeline, which is why "Penguin 5" and "Penguin 2.1" both appear in coverage from the time.
It also came just eight days after Google announced Hummingbird on 26 September 2013. Two big changes in two weeks made it harder for site owners to tell which one had moved their traffic. Hummingbird was about understanding queries, while Penguin was about links, so the diagnosis usually came down to the link profile. My post on Google Hummingbird explains the difference.
Who Penguin 2.1 hit, and what is only reported
This is where I have to be honest. Google never said what kinds of sites were hit, and I could not find a reliable published data set from the time. What we have is a pattern of reports, and the logic of how Penguin worked. Putting those together, the sites most at risk were:
- Sites that survived 2.0 with spammy links still in place. A refresh with more data could catch links the May run missed.
- Sites that kept building the same kind of links after May, such as paid guest posts, directory submissions or forum signatures with exact anchors.
- Sites whose cleanup was incomplete, for example those that removed obvious links but left a large share of exact-match anchors.
- Sites newly crossing the threshold, because Penguin judged the whole profile at the time of the run, not just changes.
The flip side is that some sites hit by 2.0, which had removed or disavowed bad links since May, had their first chance to recover in October. Reports at the time described both outcomes, which is exactly what a refresh produces.
Google's spam rules at the time and today describe the kinds of links involved. Its current spam policies define link spam as creating links "primarily for the purpose of manipulating search rankings," and list examples such as buying or selling links, excessive link exchanges, low-quality directory or bookmark links and forum comments with optimized links in the post or signature.
How Penguin 2.1 fits the full release history
Penguin 2.1 is easier to judge when you see it next to the other releases. Figures come from Wikipedia's Penguin article, Search Engine Journal and Matt Cutts' posts:
| Release | Date | Type | Reported impact |
|---|---|---|---|
| Penguin 1.0 | 24 April 2012 | Launch | ~3.1% of English queries |
| Penguin 1.1 | 25 May 2012 | Data refresh | <0.1% of English searches |
| Penguin 1.2 | 5 October 2012 | Data refresh | ~0.3% of English queries |
| Penguin 2.0 | 22 May 2013 | Algorithm update | ~2.3% of English-US queries |
| Penguin 2.1 | 4 October 2013 | Data refresh | ~1% of searches |
| Penguin 3.0 | 17 October 2014 | Refresh, "no new signals" | <1% of English queries |
| Penguin 4.0 | 23 September 2016 | Real-time, part of core | Not stated |
Two things jump out. First, at about 1%, Penguin 2.1 was more than three times the size of the previous refresh, Penguin 1.2. A bigger engine on more data caught more sites. Second, it was the last Penguin run for a year. I explain the first refresh in this series in my post on Penguin 1.1.
The year-long wait for Penguin 3.0
After 4 October 2013, there was no Penguin run until 17 October 2014. For sites hit by 2.1, that was the painful part. Because Penguin ran in batches, a site could fix everything in November 2013 and still sit under the same demotion for eleven more months.
Here is a hypothetical example of what that meant. Imagine a regional furniture retailer that lost 35% of its organic sessions on 4 October 2013, falling from 30,000 to 19,500 a month. Suppose it finished a full audit, removal and disavow by December. It would still wait until October 2014 for Penguin to re-check it. Ten months at 10,500 fewer sessions is 105,000 lost visits, on a problem it had already fixed.
The waits got even longer after that. When Penguin 3.0 finally arrived, Google said it was a "refresh," with no new signals added, per Wikipedia. Search Engine Land noted the gap of about a year between 2.1 and 3.0, and in 2015 Gary Illyes said the next refresh was "months away" while Google worked on making Penguin real-time. That finally happened with Penguin 4.0 in September 2016. I cover the October 2014 release in my post on Penguin 3.0 and its recoveries.
A lot happened while Penguin 2.1 victims waited. Google kept changing other systems, so traffic did not sit still even for sites stuck under Penguin:
- Content quality updates continued. Panda kept running, and in May 2014 Panda 4.0 hit thin and low-quality content hard. A site could lose traffic to Panda while still waiting on Penguin.
- Manual link actions kept coming. Google's webspam team continued acting on link networks, as it had since the 2012 blog network deindexing.
- Disavow files piled up. Many site owners disavowed more and more domains in the hope of being ready for the next run, sometimes including links that were actually helping them.
Recovery lessons from Penguin 2.1 that still apply
The mechanics of recovery have changed since 2013, but the habits that worked then still matter. Here is the process I would have recommended to a site hit by 2.1, and how each step looks today:
| Step | In 2013–2014 | In 2026 |
|---|---|---|
| Find the links | Export from Webmaster Tools plus third-party tools | Search Console Links report plus a link tool |
| Classify | Mark paid, network, directory and exact-anchor links | Same, but focus on clear paid or scheme links |
| Remove | Email webmasters, often with poor response | Only for links you control or paid for |
| Disavow | Essential for anything not removed | Mainly for manual actions or a known paid-link history |
| Wait | Until the next Penguin refresh | Gradual change as Google recrawls |
| Rebuild | Earn better links to tip the balance | The main lever for growth |
That last row matters. In January 2015, John Mueller said the algorithm looks at the ratio of good to bad links, so adding good links may help tip the balance, as summarized on Wikipedia. Cleanup alone rarely brought a site back to where it was, because some of its old rankings had depended on the bad links in the first place.
If you are using the disavow tool, Google's original announcement still gives sensible advice: start with the links report, and "you don't want to disavow all your links!" Our beginner lesson on bad links, negative SEO and the disavow tool explains the basics, and my guide to recovering from a link spam update explains what you can and cannot get back today.
Questions about Penguin 2.1
Was Penguin 2.1 an algorithm change or a refresh?
Google did not explain it beyond Matt Cutts' tweet, but it is generally treated as a data refresh of the Penguin 2.0 algorithm. Google did not describe any new signals.
Why was Penguin 2.1 bigger than earlier refreshes?
Google never said. The likely reason is that it was the first refresh of the stronger Penguin 2.0 engine, which had more to find on newer data. That is an inference, not a Google statement.
Could a site hit by Penguin 2.0 recover in 2.1?
Yes, in principle. If the site had removed or disavowed its bad links since May 2013, the October refresh was its first chance to be re-evaluated. Reports at the time described some recoveries alongside new hits.
How long did sites hit by 2.1 wait for another chance?
About a year. The next Penguin run, Penguin 3.0, did not arrive until 17 October 2014.
Can I still be hit by Penguin today?
Not by Penguin as a separate system. Google lists it as retired, folded into its core ranking in 2016. Link spam is now handled by core systems and spam detection including SpamBrain, per Google's ranking systems guide.
What to do if old Penguin-era links still worry you
Penguin 2.1 showed that link cleanup is not finished just because you survived the last update. Each run judged the whole profile again. Today the judging is continuous, and Google mostly ignores spammy links instead of demoting sites. But a profile built on paid or network links is still a weak foundation.
If your site has a link history from that era, or you are not sure what a past agency built, we can audit it and tell you plainly what matters and what does not. See our Google penalty recovery service, or get a quote and we will take a look.
Google updates around the same time
Before this update:
- Google In-Depth Articles (August 2013): A SERP Block for Long-Form Content (Aug 2013)
- Google Hummingbird (2013): The Rewrite Behind Conversational Search (Aug 2013)
After this update:
- Google's Panda 4.0 Update (May 2014): What Changed and Who Lost (May 2014)
- Google’s Pigeon Update (Jul 2014)
Or browse every Google update on one timeline, newest first.
Sources for this Penguin 2.1 update guide
- Search Engine Roundtable: Google Penguin 2.1 launch coverage (4 October 2013)
- Matt Cutts: Penguin 2.0 rolled out today (22 May 2013)
- Search Engine Journal: Google Penguin algorithm update history
- Wikipedia: Google Penguin
- Wikipedia: Timeline of Google Search
- Search Engine Land: Google Says Penguin Refresh Months Away From Happening
- Google Webmaster Central Blog: A new tool to disavow links (October 2012)
- Google Search Central: Spam policies for Google web search
- Google Search Central: A guide to Google Search ranking systems
