Strategy & Advisory

Improving website texts with the Flesch Index

Theresa Mühlberghuber

Digital Project Manager


March 11th, 2022


March 30th, 2022

3 min

Text on your website is very important - as it provides users with information about the company, products and services, and highlights the added value and benefits. Therefore, the wording and clarity of your website texts is essential. One way to optimise your website text is by using the Flesch Index, which we introduce in this blog post.

What is the Flesch Index?

The Flesch Index is a readability index that indicates how difficult website text is to read. It is used to evaluate the readability of text and to optimise it accordingly. In this context, the readability index is mainly used for website texts, blog articles, or advertising materials.

The Flesch Index is defined with a value between 0 and 100. The higher the value, the better the readability and consequently the understanding for the user.

The formula for the Flesch Index was developed in the 1940s by Rudolf Flesch with the goal of making newspapers more readable. The main assumption of this formula is that shorter words and shorter sentences are more understandable.

How is the Flesch Index calculated?

In short: the index is derived from the average number of syllables per word and the average sentence length. As mentioned earlier, the index yields a value between 0 and 100 - the higher, the better!

For more information on the calculation and the formula, click here.

The following table shows a rough classification of values and their meanings:

What are the advantages of using it?

As mentioned earlier, this index can be used to improve and optimise website text. It provides guidance on whether texts should be revised to make them more understandable and readable for users.

High readability of website text makes them more appealing to users, which means they are more likely to be read. In addition, users can understand the added value and benefits of the offer more quickly and effectively, which in turn can support conversion.

Furthermore, a high reading ease score also supports the SEO ranking of the website. Due to the appealing and understandable texts, users spend more time on the website, which increases the session duration. And a high session duration is a very good indicator for search engines that the content is relevant and interesting.

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Before and after example

As an example, I will now improve a text block from our website. This is the original text:

"We are Momentum - the innovative Tyrolean web design company. With Website as a Service (WaaS), we have developed a new approach to websites. We not only create them, but also manage your entire website. We create websites that reflect the performance of your business online and thus drive your business forward."

The goal is to revise the text so that the readability score increases while maintaining the statement. Therefore, I tried to shorten the sentences and avoid using jargon, to make the text more understandable. I looked for synonyms for individual words and rephrased the corresponding text passages.

Here is the result:

"We are Momentum. We use our new approach, Website as a Service, to develop our websites. We advise you from concept to implementation and take over the management of your website. This way, we create websites that show the performance of your business and meet your goals."

Before and after comparison:

Before (38 points)

After (54 points)

The calculation was performed using the "Flesch Index Calculation" website. With it, you too can easily check the readability of your own texts online!

As the scores show, the text was classified as "difficult" with 38 points before the revision. After the revision, the score was increased to 54 points and is therefore to be interpreted as "moderately difficult". With the help of the Flesch index, we were able to improve our text, but it is still moderately difficult.


The Flesch index is a useful tool for improving website texts and quickly and easily determining whether texts are easy to understand or not.

Attention: It is important to mention that the index does not evaluate the content. Thus, a meaningless text can also achieve a very high score.

Text optimization should therefore not be aimed at the highest possible score, but rather a combination of clarity and substantive quality. Otherwise, there is a danger of creating texts that are meaningless to the user.

However, the Flesch index helps to identify weaknesses and support revision.

Not sure if your website texts are understandable or need help with wording? We would be happy to support you with SEO-compliant copywriting! Here you can find our contact form - or call us directly at +43 677 61641617.


Get in touch with us to see if we can help


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