Few areas of SEO have been reshaped by Google updates as heavily as link building. In 2011 you could still buy a directory package, spin a few hundred articles and watch rankings climb. By 2012 Penguin was demoting sites for exactly that. A decade later, Google’s link spam updates and its AI-based spam system had made most manipulative tactics simply worthless.
Yet links still matter. Google’s own ranking systems guide says link analysis – including PageRank – remains part of how it understands which pages are helpful. The question is not whether to earn links, but which kinds still count.
This guide traces what Penguin and the link spam updates changed, which practices survived, which were neutralised, and how to build a link profile that does not need to fear the next spam update.
Key Takeaways
- Since Penguin 4.0 (2016), Google mainly devalues spammy links rather than demoting whole sites, so bad links increasingly waste money instead of causing penalties.
- The July 2021 and December 2022 link spam updates aimed to nullify unnatural links; Google said the 2022 update used SpamBrain.
- Editorial links earned through useful content, digital PR, original data and real relationships still work.
- Paid, sponsored, affiliate and user-generated links are fine when qualified with
rel="sponsored",rel="ugc"orrel="nofollow". - Manual actions for unnatural links still exist, so large-scale schemes remain a real risk.
How Google’s link updates evolved
The table below summarises the key confirmed milestones. Dates come from Wikipedia’s timeline of Google Search, the Search Status Dashboard and Google’s documentation.
| Update | Date | Confirmed? | What changed for links |
|---|---|---|---|
| Penguin | 24 April 2012 | Yes | Webspam algorithm targeting link schemes and keyword stuffing; about 3.1% of English queries affected |
| Penguin 2.0 | 22 May 2013 | Yes | Looked deeper than the homepage; about 2.3% of English queries |
| Penguin 3.0 | 17 October 2014 | Yes | Refresh more than a year later; some demoted sites recovered |
| Penguin 4.0 | Announced 23 September 2016 | Yes | Became part of the core algorithm, ran in real time and devalued bad links instead of demoting sites |
| July 2021 link spam update | 26 July – 24 August 2021 | Yes | Nullified spammy links across languages; Google reminded sites to qualify affiliate, sponsored and guest-post links |
| December 2022 link spam update | 14 December 2022 – 12 January 2023 | Yes | Used SpamBrain to detect sites buying links and sites used to pass outgoing links |
Our post on real-time Penguin and the write-ups on the July 2021 and December 2022 link spam updates cover each one in more detail. Google also lists Penguin as a retired system in its ranking systems guide, describing it simply: “This was a system designed to combat link spam.” Its job now sits within Google’s core and spam systems – see our SpamBrain explainer.
What Google counts as link spam today
Google’s spam policies define the problem in one sentence:
“Link spam is the practice of creating links to or from a site primarily for the purpose of manipulating search rankings.”
— Google Search Central, Spam policies for Google web search
The policy then lists examples. Under buying and selling links it includes exchanging money for links or for posts that contain links, exchanging goods or services for links, and sending someone a product in exchange for them writing about it and including a link. The key word throughout is primarily: the problem is links whose main purpose is ranking manipulation, not links in general. Our full guide to Google’s spam policies covers the other categories.
What still works vs what has been neutralised
| Practice | Status in 2026 | Why |
|---|---|---|
| Editorial links earned by useful content | Works | Exactly the kind of signal link analysis is designed to reward |
| Digital PR with newsworthy data or stories | Works | Journalists link because the story is useful to their readers |
| Original research, tools and linkable assets | Works | Earns citations over time without payment |
| Real partnerships, suppliers, associations, local sponsorships | Works if genuine | Reflects real-world relationships; qualify paid sponsorships |
| Guest posts written for an audience | Limited value for rankings | Fine for exposure; Google asks for keyword-rich guest-post links to be qualified |
| Paid links passing ranking credit | Neutralised or risky | Listed as link spam unless qualified with rel="sponsored" or nofollow |
| Private blog networks (PBNs) | Neutralised or risky | Sites used to pass outgoing links were a target of the 2022 update |
| Large-scale link exchanges | Neutralised | Excessive link exchanges are listed in Google’s spam policies |
| Comment, forum and profile spam | Neutralised | User-generated links are usually ugc or nofollow and are a spam policy issue |
| Exact-match anchor text at scale | Risky | Unnatural anchor patterns are a classic link-scheme footprint |
How to qualify links properly
Google’s documentation on qualifying outbound links gives three values:
rel="sponsored"– for links that are advertisements or paid placements.rel="ugc"– for user-generated content links, such as comments and forum posts.rel="nofollow"– when the other values don’t apply and you don’t want to vouch for the link.
Qualifying paid links is not an admission of guilt; it is how you buy advertising or sponsorships without breaking the spam policies. See our guide to sponsored links for practical examples.
A link building process built for the update era
- Audit what you have. Review your backlink profile for paid, exchanged or network links. Most spammy links are probably being ignored already, but you need to know if a manual action risk exists.
- Clean up only what matters. Remove or qualify links you control (sponsored posts, partner pages). Reserve disavowing for clear, large-scale problems – our guide to toxic backlinks and disavowing explains when it is justified.
- Create something worth citing. Original data, expert commentary, free tools and genuinely useful guides attract links far better than outreach volume.
- Run targeted digital PR. Pitch stories and data to journalists who cover your industry. Our digital PR for SEO guide covers the process.
- Build real relationships. Suppliers, partners, associations, events and local organisations are natural sources of relevant links.
- Measure quality, not just counts. Track referring domains that are relevant and send real visitors, not just a domain metric.
- Keep everything explainable. If you could not comfortably explain a link to a Google reviewer, do not build it.
What to do if a link spam update hit you
When Google nullifies links, the rankings those links were propping up fall away. Recovery is less about “removing the penalty” and more about replacing lost value with links that count. Our step-by-step link spam update recovery guide covers how to tell a link-related drop from a core update drop and how to rebuild.
- Check Search Console for a manual action first; if there is one, clean up and file a reconsideration request.
- If there is no manual action, assume an algorithmic devaluation: stop buying links and focus on earning new ones.
- Look at whether the drop coincided with a confirmed link spam or spam update on the Search Status Dashboard.
Common mistakes
- Believing “PBNs still work”. Short-term gains often vanish at the next spam update, along with the budget spent.
- Mass disavowing in a panic. Disavowing good links can do more harm than good.
- Buying “guest posts” that are really paid links. If money changed hands for a followed link, it falls under link spam.
- Chasing domain metrics instead of relevance. Third-party scores are not Google metrics.
- Forgetting to qualify affiliate and sponsored links on your own site. Outgoing link spam is a policy issue too.
Related Guides
- How Google Updates Have Affected Affiliate Sites (2011-2026)
- How Google Algorithm Updates Affect Local Businesses
- How Google Updates Affect Ecommerce Sites
Frequently Asked Questions
Does link building still work after Google’s link spam updates?
Yes. Editorial links earned through useful content, digital PR and genuine relationships still help. What stopped working are links created mainly to manipulate rankings.
Will bad backlinks get my site penalised?
Since Penguin 4.0, Google mostly devalues spammy links rather than demoting whole sites. Manual actions for unnatural links still exist for large-scale schemes.
Should I disavow links after a link spam update?
Usually only if you have a manual action or know of a large number of paid or artificial links you cannot remove. Most sites do not need to disavow.
Are guest posts allowed?
Guest posting for exposure is fine, but Google asks that keyword-rich or paid guest-post links be qualified, for example with rel="sponsored" or rel="nofollow".
What is SpamBrain’s role in link spam?
Google said its December 2022 link spam update used SpamBrain to detect both sites buying links and sites used to pass outgoing links.
Conclusion
The lesson of Penguin and the link spam updates is simple: links that would exist without search engines are safe, and links that exist only for search engines are increasingly ignored. Invest in content and relationships that earn citations, qualify anything paid, and you can stop worrying about the next spam update. If you want help auditing your link profile or planning a clean digital PR programme, get a quote from our team.
References
- Spam policies for Google web search (Google Search Central)
- A guide to Google Search ranking systems (Google Search Central)
- Qualify outbound links to Google (Google Search Central)
- Timeline of Google Search (Wikipedia)
- Google Search Status Dashboard: ranking incident history
- Link building for SEO: What works in 2026 (Semrush blog)
