What Are Backlinks?

Backlinks are references from one domain to another. Users can click these links to reach the linked page. Backlinks are an important ranking factor for Google.

To put it briefly: If the online edition of Forbes Magazine writes an article about the past Google Core update in June 2019 and links to our site there, we have received a backlink from Forbes:

Why are backlinks so important?

Google has evaluated backlinks as a signal of trust between domains from the very beginning. The basis for the search algorithm was the famous PageRank calculation. It analysed the links between different pages and deduced how trustworthy a particular website was. This allowed Google to display better search results, and it became the most powerful and relevant search engine.

Even today, Google still uses a PageRank calculation internally. Although this is far more comprehensive and efficient than the calculation defined in the PageRank patent, it is still based on links.

Thus, backlinks are still one of the most important ranking factors for Google today.

Building a Backlink

Every backlink has a similar structure and provides varying information to browsers and search engines.

This is what you need for a link

  • It is important that each link is introduced with <a href>. The <a here introduces an anchor element. The href defines this element more precisely. href is short for “hypertext reference” and refers to the location where the browser finds the linked document.
  • In addition, the browser still needs text or a graphic element under which the link can be found. In our case, we will select “SISTRIX” as the anchor text.
  • The anchor element is closed again with </a>.

So, the pattern is:

<a href="URL">link text</a>

Our link now looks like this:

<a href="https://www.sistrix.com/blog/google-core-update-more-content-and-news-sites-affected">SISTRIX</a>

This is how you give the browser additional information

There are also various attributes that are not necessary for the link to work, but that provide search engines and browsers with additional information. It is possible to specify very precisely where the browser should open a link:

  • target="_blank" will cause the link to open in a new window. The best choice for external linking.
  • target="_self" is the default setting and causes the browser to open the link in the same tab, thus “overwriting” the current page. This can be useful in the context of internal linking.
  • target="_parent": The browser opens the link in the parent frame.
  • target="_top": The browser opens the link in the highest-ranking tab.
  • framename: The browser opens the link in a new tab with the name set in this way.

For our example, this means:

<a href="https://www.sistrix.com/blog/google-core-update-more-content-and-news-sites-affected/" target="_blank">SISTRIX</a>

Information for Search Engines

In addition, there are some attributes that are especially important in the context of SEO. They specify the relationship to the linked page, so you preface it with “rel=” for “relationship”. These are your options:

  • follow: You do not need to provide concrete attributes for such links, as it is basically the default. With such links, you instruct search engine bots to switch to the page.
  • nofollow: With “nofollow” on the other hand, you indicate that you do not want to be directly associated with the linked website, nor do you want to pass link power to it.
  • sponsored: This attribute shows search engines that the link recipient has paid for this link. As a result, these links are not weighted for the ranking of the linked page.
  • ugc: ugc is short for “user generated content”. You can use this to mark links in forum posts or comments, in order to distance yourself from these links to some extent.

So, one way to implement a nofollow link would be:

<a href="https://www.sistrix.com/blog/google-core-update-more-content-and-news-sites-affected" rel="nofollow" >SISTRIX</a>

Quality over Quantity

Backlinks are important to measure the quality of a website. Hereby, the quality of the links is given greater importance than the quantity of links. The quality is determined by the search engines based on various properties.

If you want to build good backlinks, you need to keep the following quality characteristics in mind:

  • Quality and authority of the linking site: A well-known website with high-quality and carefully researched content is a valuable link giver.
  • Traffic: A meaningful link creates traffic. Google knows this (and in all likelihood measures this as well).
  • Position of the link: Many readers quickly back out. An earlier link creates more traffic and is considered more relevant to the content.
  • Thematic similarity: A link from a small business magazine is more valuable for an insurance broker than a link from a well-known beauty magazine.
  • Age of the link/post: Regularly updated content also has a positive effect on link quality.
  • Link text: This used to be almost the most important part of a link, but its importance has now declined.

Google wants to prevent websites that only offer low-quality content from achieving a higher ranking by buying backlinks. In the early years (before 2012) it was relatively easy to bring bad sites to the top of the search engines on Google. Buying cheap backlinks was enough to do so. Google has been working on a weapon against this link spam for a long time, and created an algorithmic solution for it in 2012 with the Google Penguin update. The Penguin update has evolved over the years and can now detect and automatically devalue the majority of low-quality purchased links.

What is an organic link profile, and why is it so important?

When building links, it is important to remember that buying backlinks is prohibited by Google in the Webmaster Guidelines. However, it is equally important to know that link building does not only consist of link buying. You can read more about this in our deliberately provocative article: Only fools will ignore link building. Spoiler: link building is difficult, expensive and annoying.

An organic or “natural” link profile is recognised by Google as a special quality feature. While analysing backlinks, the search engine ultimately only tries to find out which pages are considered particularly valuable by others. Thus, link building happens relatively chaotically.

On one day, a website owner may link to a page with a nofollow link, on another day, the page receives a link through a forum post and again on another, an admin enters it into five appropriate directories. The forum member may use an anchor like “this page”, the admin may use the brand name and the website owner may use “more info”.

In this way, a backlink analysis with a backlink checker provides a very versatile picture of a wide range of sources, linking types and anchor texts. And while fewer links tend to be placed on a website in the beginning, organic link building picks up speed over time.

On the other hand, a link profile looks entirely different when someone conducts extensive link building through link purchases. The link profile grows inorganically, too many high-quality pages link to the website in a short time with perfect anchor texts and there are proportionally more follow links than nofollow links. Whenever these patterns appear, it is likely that the page was pushed with link purchases.

Buying backlinks is not forbidden, but if Google detects violations, it can lead to lower rankings.


Backlinks form the neural pathways of the World Wide Web and are incredibly helpful and important for users as well as Google to tap into new and interesting content. Every webmaster should familiarise themselves with link building measures beyond link buying.

Google may not be able to detect each and every paid link yet, but link buying is never expandable without Google becoming aware of it sooner or later. And without well-founded link building, any website will fall short of its potential. Watch our Ranking Factors videos on the topic of links to get a good introduction to the subject.

What Google says

There's no such thing as building too many links, as long as you're doing it in a great, organic way. (...) The real objective in making a successful website, is to make something that's so awesome that you get the links basically for free. (...) Those links will come naturally.

Source: Matt Cutts

Our Google Conclusion

Links are an important criterion for Google to determine the trustworthiness of a website. However, Google is very good at recognising which links are trustworthy, organic and actually clicked by users – and which are not.

Steve Paine