To represent the visibility of a website in Google’s search engine rankings as a measurable value, the “visibility index” is used as an indicator. Visibility is based on the ranking of individual keywords used on the page. There are different bases for calculating the visibility index. For this reason, the values may differ depending on the tool that is used.
The graph shows the development of the Sistrix visibility index of the website eology.de visually. It can be clearly seen that the SI was only just above the value 0 until 2016. In the period between 2016 and 2021, however, there is a clear increase to a visibility index of approx. 0.5.
Different methods are used to calculate the visibility, depending on the tool, but at the core all tools are based on the same foundation. First, the 100 highest rankings of several hundred thousand, if not millions of keywords are determined. The Sistrix visibility index, for example, accesses a keyword pool of about 250,000 keywords.
In the next step, the rankings are set in relation to the expected traffic from the positioning of the keyword and the expected traffic from the keyword itself. In summary, the visibility index is made up of these three basic factors.
The visibility index only takes into account the previously defined keyword pool and puts this in relation to a traffic probability. For this reason, you should not expect a clear statement, but consider the visibility index as a guideline or approximate value. The actual traffic generated by a website may well deviate from these values. Especially when viewed in isolation, the visibility index hardly offers any informative added value at first glance. In combination with other factors, however, it can become a very powerful weapon for SEO. One of these factors would be time, so dips or fluctuations can be easily read over a longer period of time and thus enable timely intervention. Another factor would be, for example, the comparison with competitors. In addition, conclusions about events or measures can be drawn from the course of the visibility index, which can be very helpful for optimization processes.
Especially with more specific pages that use less common keywords, it can prove difficult to determine a reasonable visibility index. The reason for this is easy to explain if you are familiar with how visibility is determined. The principle is simple: the top 100 rankings are determined for all keywords in the pool. However, if the keywords used are not common but niche keywords and most of them are not included in the pool, no index can be determined. As a result, the affected pages would inevitably have a low visibility index and only limited possibilities to increase it.
The clear go-to is Sistrix. It is the most common tool when it comes to determining how visible a website is. Nevertheless, there are alternatives. Other well-known tools are therefore: