Visibility Index

What is the visibility index?

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.

Example of a visibility index

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.

How is the visibility index calculated?

The calculation of the visibility index is based on several factors that together provide a meaningful indicator of the organic visibility of a website. First, the keywords for which a page ranks in the search results are determined. These keywords are weighted according to their search volume and their relevance, i.e. the search intention. Then the position of the keywords in the search results is analysed, with higher-ranked keywords having more influence on the index. Another important aspect is the probability of a click (click-through rate, CTR), which shows how often a search result is actually being clicked. The combination of these factors results in the final visibility index, which may vary depending on the SEO tool. Tools such as Sistrix, XOVI or SEMrush use different data sets and methods to calculate the index and use it as an indicator for the performance of a website.

In summary, the visibility index is made up of these three basic factors.

1. Ranking of the determined keywords
2. Traffic resulting from the positioning
3. Traffic resulting from the keyword

Desktop vs. mobile visibility index

One crucial factor in calculating the visibility index is the difference between desktop and mobile visibility. As more and more users perform searches on mobile devices, website rankings often differ between desktop and mobile. This is mainly because mobile optimisation plays a greater role: websites that are not sufficiently optimised for mobile devices perform worse in mobile search. Tools such as Sistrix and XOVI take these differences into account and offer separate indices for both platforms. One example of this is that mobile rankings are more heavily influenced by loading speed and usability on small screens. Therefore, when optimising a website, both the desktop and mobile versions should be considered to ensure the best possible visibility.

This distinction allows for more precise analysis and shows where there may still be room for improvement for mobile users.

How meaningful is the visibility index for SEO?

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.

What difficulties arise when determining visibility?

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.

Which tools are used to measure the visibility index?

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:

• ahrefs – there, the so-called Domain Rating is measured, which indicates the visibility of a page
• MOZ – with the Domain Authority, MOZ also creates a counterpart to the visibility index of Sistrix
• Xovi – with OVI (Online Value Index), this tool measures the visibility of a page.

Tips for increasing the visibility index

Here are some helpful tips for sustainably improving the visibility index:

• Optimise keyword research: not only find relevant keywords with high search volumes, but also analyse the users’ search intention to ensure that your content offers exactly what they are looking for.
• Holistic content: Create comprehensive content that covers a topic from different angles. This not only strengthens your ranking for generic keywords, but also covers long-tail keywords.
• Mobile optimisation: Make sure your website is mobile-friendly. A fast loading time, intuitive navigation and an adaptable display on different devices contribute significantly to better mobile visibility.
• Optimise meta data: concise and well-written meta titles and descriptions can increase the click-through rate, which has a positive effect on the visibility index.
• Analyse the competition: analyse your competitors’ keywords and content. Identify gaps in content and find out which topics are not yet sufficiently covered to discover new potential for your website.