What is black hat SEO?

Black hat SEO refers to prohibited search engine optimisation methods that attempt to manipulate a website’s ranking—usually by deceiving or bypassing Google’s guidelines. Black hat SEO tricks can bring short-term success but often lead to penalties or even removal from the Google index in the long run.

What is behind the term ‘black hat SEO’?

The term black hat is now mostly associated with hackers but originally comes from an entirely different context: in classic Western films, the villain typically wears a black hat during a duel, while the hero wears a white hat. The term black hat SEO can be described in many ways, but the image of something shady and impermissible remains. For some, it is simply unscrupulous methods of generating links, for others, it is clearly spam practices. In any case, black hat SEO techniques are used to bypass official search engine quality guidelines to gain an advantage over competitors.

When launching a new website, businesses often face a long road to reach top positions on Google, Bing, and similar search engines. To achieve these top rankings, they must build a reputation and earn user trust. They must also generate the signals Google uses to evaluate sites. One key ranking factor is the domain trust—the level of credibility or trustworthiness Google attributes to a website.

The idea behind black hat SEO is to fake reputation and trust. In other words, the site pretends to be more relevant, popular, and authoritative than it really is. If Google detects violations of the Google Search Essentials resulting from black hat SEO techniques, it takes tough action. The pages are penalised and, in the worst case, removed from the Google index entirely. Thanks to Google’s AI-based system RankBrain, which considers not only keywords but also user behaviour and context to better understand content relevance, black hat SEO techniques are increasingly detected because they can no longer outsmart semantic analysis.

An overview of black hat SEO techniques

A big part of SEO is called off-page optimisation. This involves promoting a site ‘from the outside’. The goal is to get positive signals (i.e., links) from third parties. Each link pointing from another website to your own acts as a kind of recommendation for Google. Collecting as many recommendations like these as possible is not forbidden, as long as the backlinks are acquired naturally—for example, by creating high-quality content that users enthusiastically share. Black hat SEO, however, aims to obtain these links without the effort of extensive content creation and marketing campaigns.

Other black hat SEO practices aim to improve rankings without investing time and money in content marketing or social media marketing. Below are some of the most common black hat SEO techniques.

Doorway pages

Doorway pages are pages optimised only for search engines and invisible to actual users. These ‘bridge pages’ are filled with Google-relevant keywords but are never seen by users because they act solely as intermediate pages that redirect visitors directly to the actual website. The goal is to increase the link popularity of the target site and improve its ranking. While this tactic used to be common, it is now largely ineffective because Google clearly considers doorway pages a guideline violation and therefore a manipulation attempt.

Cloaking

With cloaking, two different versions of a website are created under the same URL—one for search engines and another for human visitors. A script can distinguish whether it is a search engine bot or a real user. The bot is shown a search-engine-optimised version, usually with more text and heavy keyword use. The user version is visually richer, often with multimedia elements such as videos. The reason is that search engine indexing primarily relies on text because most other elements are invisible to a crawler. On the cloaking page, these elements are replaced with SEO text. Search engines now easily detect cloaking and penalise it, often removing sites like these from the index.

Link buying

A widespread and still frequently used black hat SEO trick is unnatural link building through purchased links. As the name suggests, backlinks are not acquired organically but simply bought. The goal here is also to increase link popularity. However, Google values natural link building that results from high-quality, up-to-date content. Google’s guidelines prohibit buying, selling, exchanging, or renting links. Violations lead to ranking losses or exclusion from the index—if discovered.

Particularly risky are so-called private blog networks (PBNs). These are artificially built link networks created solely to generate backlinks. A special form of link buying involves purchasing so-called Russian links, cheap backlinks acquired from abroad, mainly Russia. Google now consistently penalises these practices.

Keyword stuffing

Keyword stuffing refers to over-optimising keyword density—placing as many keywords as possible in a text to make it seem more relevant to Google. This type of manipulation dates back to the early days of SEO and is now ineffective. Thanks to numerous Google algorithm updates, websites engaging in keyword stuffing are quickly filtered out, and Google penalises such pages.

Hidden content

Hiding text or links is another classic black hat SEO technique from earlier times. The tactic involved promoting relevant keywords by placing them, for example, in white text on a white background. This was intended to trick search engines into believing the content was relevant without overwhelming users with visible keyword spam. Links were also hidden similarly, sometimes behind small symbols (like a hyphen). Google now detects hidden text and links and also considers them manipulation attempts.

Thin AI content and AI spam

With the rise of generative AI tools, search engine manipulation has evolved. Increasingly common are thin AI pages—websites whose content is created using artificial intelligence but offers little real value to users. While these pages can be produced quickly, they typically consist of superficial, meaningless text lacking depth.

Google has responded with several algorithm updates that reliably detect AI generated spam content. These pages risk ranking downgrades or even full removal from the index. Once again, what seems easy in the short term can cause significant long-term damage.

How to optimise with a clean conscious

All these examples show that black hat SEO techniques may promise short-term success, but they are extremely risky in the long term because Google eventually detects many of these manipulation attempts.

The penalties vary in severity, ranging from ranking drops of up to 30 places to being completely removed from the index. Once penalised and demoted, it is extremely difficult to regain top positions, let alone the first page.

It is more sustainable to follow guidelines and approach search engine optimisation with a clean conscious. However, with numerous rules and regulations, fully compliant white hat SEO is challenging. This creates a grey area often referred to as grey hat SEO. Here, available SEO measures are pushed as far as possible without triggering penalties from Google. Grey hat SEO is essentially a balancing act of using borderline tactics to improve link popularity and rankings while staying below the penalty threshold. Most companies and agencies operate within this grey zone.