Readability and SEO: How Are They Related?

There are plenty of factors for appearing on the top list of the search pages. The traffic of the website, social media sharing, the quality of HTML code, the age range of the visitors are examples of these factors. Sometimes, it is not taken seriously but the lack of complexity of the texts on your content is also very important for increasing the search ranking. This factor is called “readability” and it can be measured by “readability score”. Explore readability and SEO relationships now!

SEO is standing for “Search Engine Optimization” and it is useful for search engines to understand the content on the websites and highlight them to the top. To increase the chance of appearing on the first pages of the search engines, you have to shape the infrastructure, design, and content carefully and available for the criteria of the search engines. So that, the SEO and website are optimized and the ranking of the website gets higher.

Keywords, the structure, length, etc. of the texts in the contents are important points to be careful about. These factors affect readability and readability affects SEO.

Do you want to increase your website traffic?

Try for free to boost your website traffic!

Readability and SEO: What is Readability?

Readability is very important for SEO and keeping your audience in your hand. Even, it can be more important than the subject of the text. Sometimes people read the texts if it is readable even though the subject is irrelevant to them. Good text has to be readable if you want it to be understood by your audience. So, you have to know your audience. For example, you need to know the average age or range of age. If you do so, you will start to change the tone or the words of the texts to turn them more readable for your audience.

Readability and SEO: What is Readability?
Readability and SEO: What is Readability?

If the text is not readable, the subject cannot be understood, the audience gets bored and leaves your website. As these leavings are increased the website traffic will decrease day by day. So, when the search engines notice that your website will not have appeared on the first pages of the search. This will damage the reputation of your website. If your text is readable, the circulation of the audience would increase. Also, the audience will start to wander around your website to search for another text to read.

If you wonder how the readability measure, there are a couple of formulas for it. Also, some key factors affect readability. All of them are mentioned in the following.

Test Your Website Issues

You can quickly analyze your site

The Factors that Affect Readability

The factors that affect the readability are based on the structure of the texts, sentences, the words you choose, how many times you use the same words, the complex sentences, and hard words, and goes on. These factors are mentioned below. After you read these factors search a random subject in the search engine and click on the first result. You will realize that these texts in the content all follow these factors to appear on the top since the readability index is one of the most important things that affect it.

The Factors that Affect Readability
The Factors that Affect Readability

The length of the sentences

The optimal length of the sentences can be varied according to the content but try to keep the sentences as short as possible. They have to be direct, simple and lack unnecessary words. For instance, you should use the “can” word instead of “be able to”. Also, you may avoid the usage of “actually”, “usually” or “definitely”. Even though you think these are supporting words for the text, they are only working for making the text crowded.

If it is necessary, you can use prepositions and adjectives. However, it is important how you use it. For example, if your sentence is “This beautiful flower has purple leaves and smells very good” try to split it. Then, re-arrange as “The flower has purple leaves. It smells very good”. In this way, your audience will not be tired while they are reading. Also, the text would not look intimidating to them so, they would not leave your page.

The structure of sentences

The knowledge of the subject, predicate, and subject are the main elements of the sentences’ structures. So, you have to be careful about the usage of these elements while you are building up your sentences. Also, try to avoid using inverted sentences to prevent the crowd in your texts. It is valid for every language. The sentences should be structured as simple as they can be. If it is possible, don’t contain sub sentences or very complex sentences in your texts.

The structure of the text

The structure of the text is the main thing that the formulas below consider for the calculation. Your texts should be split up into paragraphs. However, don’t build paragraphs for every sentence distribute the subjects to them. The ideal paragraph has about 5 to 6 rows. Don’t forget to give a title to your text, also the subtitles are as important as the main title. Listings can also work well for improving readability. 

The usage of the words

The keywords are the skeleton for the texts and you should use them more often than the other words. However, don’t use them in every single sentence, that would be very meaningless. Use them in where they are needed for sure. Avoid using words that cut off the flow of the content. These words can be hard or old-fashioned. Also, the over usage of conjunctive adverbs would cut the flow and make the text non-sense.

Don’t use a specific word besides the keywords many times, it would not serve anything good for you. Hard words can be your enemies. Hard words are defined as words that have more than 3 syllables. We don’t say use them again but try to use them carefully and as little as it can be. Also, using too many foreign words would decrease the readability, but if you write the meanings of them in the description box, it would be an advantage for you.

Visual arrangements

Your text should be visually appealing that the people want to read when they see it for the first time. Try to use some colors in your text. Maybe, you can give vibrant colors to the titles or make a specific paragraph in different colors. Even, underlining or making the words bold work for giving an extra dimension to your text. You may also highlight with vibrant colors the important points such as the keywords or the link attachments.

Tables, images, graphs, schemas, or sometimes videos are very powerful supporting tools for the text. They increase the readability of the text. Tables and schemas are making it easier to make people understand the subject. Images and videos would small breaks between the paragraphs, so the audience can regain their attention. However, you should be careful about the graphs. Choose the simplest graphs; complicated graphs would be very bad for the readability.

Further factors

For further factors, use descriptions for your images, graphs, videos, tables, or schemas. The audience should be sure about what they are seeing right now. The descriptions should not be too long or too short. You can’t just say “apple and girl” as a description you should change it into “a girl eating an apple”. Use headlines and make the chronological order work for you. Don’t use <h3> tag before <h1> tag.

The font of the text is also very important. You can use the most classical ones but avoid the ones with different effects such as the ones with shadows, 3D structure, stripes, etc. That would look like a presentation of a primary school student. The size of the font should be chosen carefully. If it too small, people would leave your website immediately. If it is too big, it would like very unprofessional, childish, and frivolous. 11-12 points for the texts usually work.

The line gap should be arranged carefully. If the lines are too close to each other it would not be appealing for readability. If you are not focusing on a specific subject and writing general content the words should be very simple. If you have to use some terms about certain subjects, then you have to add descriptions to them and also not use them many times. As it is mentioned before, adjectives should be used limited. Also, avoid adjective phrases that contain more than one adjective such as “stunning blue sky”.

The Formulas of Readability

To measure the readability of the text there are certain formulas used. These are all mathematical formulas and some of them can be obtained for free but some of them can be paid for. These formulas are given readability scores for your texts which can remind you whether you are passed on the test or not. There are some variables in these formulas such as the hardness of the words. However, this variable cannot be applied to all of the languages. Maybe, it is the smallest gear but it certainly moves the bigger gears and makes the SEO work properly.


The Flesch-Kincaid formula is the most commonly used one and was found by Rudolf Flesh and Peter Kincaid. There are two variables in the formula which are the number of syllables and the total number of sentences found in every 100 words. For calculating the length of the words, the number of syllables is divided by the number of words. On the other hand, for calculating the length of the sentences the number of words is divided by the number of sentences.

Flesch-Kincaid  - Readability and SEO
Flesch-Kincaid – Readability and SEO

As the result, the number of the syllabus for each word is observed. 121.2 is the very top score for this formula and it means it is the easiest test. As the score get decreases then, the text is getting hard to read. You can use their website for the test.

Gunning Fog

Gunning Fog formula is found by the inventor with the same name. There is a constant number in this formula which is 0.4. Also, the words with more than 2 syllables and an average number of words in the sentences are used as two variables in this formula. If the result is greater than 10, then the text is very hard to read. Even though the number of syllables is not the same for all languages, Gunning Fog test can be applied to the common languages.

Dale Chall

Dale Chall is developed by Edgar Dale and Jeanne Chall and their formula is based on the first 100 words. They believe that the formulas based on semantics are more successful. They state that if the unknown and hard words were high in number and repeated many times, then that text was hard to read. This test can be applied to only English tests since the “unknown and hard words” list is prepared by English words.

There are two variables in this formula which are the length of the sentences and the ratio of “hard words”. To find out the length of the sentences the number of words is divided into the number of sentences. The ratio of the hard words by dividing the number of hard words by the rest of the words and multiplying it by 100. You can test your texts’ readability from their website for free if they are in English.


Ari is standing for Automated Readability Index and developed by Senter and Smith in 1967 which is used by the USA army. It is not commonly used in the present and it is not covering enough parameters. It calculating the number of characters of the length of the words with the addition of quantity. So, it is given information about the age range that your text is targeting.


Fry formula is developed by Edward Fry and it is only applicable for English texts. The average number of sentences in which the number of syllables in the whole text and the special words is subtracted is calculated. From the beginning, middle, and ending 100 words are taken as the base of the formula. It has quite a complex formula and the results are given as graphics. You can calculate from their website for free.


Smog formula is developed by G. Harry McLaughlin and it is probably the easiest one among all of them. There is only one variable in this formula. The average of the words that have more than 2 syllables in 30 consecutive sentences is calculated. For the agglutinative languages such as Korean, Turkish, etc. this formula can be insufficient. It works best with English.


Ateşman formula is found by Ender Ateşman and it is only applicable for Turkish texts. The researches show that the length of the sentences in Turkish is consist of 10 words in average. The average syllables of the length of the words are 2.6. It is the best for Turkish texts. There are two variables in the formula. In the first, the average length of the words comes out as syllables. For the second variable, the average length of the sentences is calculated as words. For the score, 100 is the easiest, and 0 is the hardest text to read.


Coleman-Liau is developed by Meri Coleman and T. L. Coleman. This formula and test do not focus on counting the number of syllables. Instead, it counts the length of the words by letters. It is commonly used especially in the law, medicine, and translation areas. 

The Importance of Readability and SEO for Search by Voice

Readability is a very important element for searching by voice in search engines. While you are preparing your website by thinking about these users, the texts of the contents should be easy to read. Some people prefer this way but some blind individuals use it. If the users search by voice, they would not want to listen to pages of stories. They want to get the answer in a couple of sentences that are clear and simple.

The Importance of Readability and SEO for Search by Voice
The Importance of Readability and SEO for Search by Voice

Google and the other search engines would present and highlight the contents that are readable to their users. This content would be the first result that appeared on the search page or the one that appeared as featured snippets. If the content includes, hard and complex words or sentences, the reading of the search by voice and understanding by the user would be very hard. Moreover, Google would not highlight that content and throw it to the far pages.

Readable Text Are Important for the Users’ Experience

The key point while you are writing the texts for the contents is giving to the audience qualified, original and creative ones. The qualified contents must be readable. Readable contents would be understood easily and fluent expressions would increase the readability even higher. Fluent expressions are loved by the audience and the traffic on your website gets higher. At this point, the keyword should not be too much that can be considered as “spam”. Also, the texts should not be left as bulk and split into meaningful paragraphs.

Simple, fluent, short paragraphs, easy word choices, short sentences, and listings are the key factors that influence the users’ experience positively. These kinds of content are direct content. They are widely preferred by users while they are looking for an answer. So that, finally you build up the SEO strategy you need.

Readability and SEO can be confusing subjects sometimes. If you have more questions in your mind about the relationship between readability and SEO, don’t worry. Here are some frequently asked questions and their answers we gathered for you. Let’s review!


What should be the good readability score for SEO?

The readability score varies according to the type of formula used. However, since the Flesch-Kincaid is the most common one let’s consider it. Even the highest score is 121 for this test, the scale of it originally 1 to 100. As the score gets lower, the text is hard to read and vice versa. The texts around 100 can be read easily which consist of short sentences and words with less than 3 syllables. If your score is between 60 to 70, it is acceptable and normal to read. Try not to go lower than them.

Is high readability score better?

A readability score defines the easiness of texts as reading-wise. For all of the tests and formulas, the highest score of the test has the easiest readability where it is the opposite for the lowest score. So, yes high readability score is better. However, if you get a score between 60 to 70, it would be enough score for readability.

Is Google ranking affected by readability?

Yes, Google ranking is affected by readability. In general, the Google algorithm tries to mimic human beings to improve themselves from the perspective of the targets. Google tries to read the text as if it is a human. So, if Google would be able to understand, scan and define the texts as mimicking humans, the readability of your texts would become more important for the Google rankings.

How readability is improved by SEO?

Apply all the factors mentioned above. If they are not enough for you, try to write your content in a conversational tone. It would be the thing that your audience likes since it is a very sincere and easy tone of expression. Also, before you publish your text read it out loud. You can read either by yourself or to someone. You will notice if the text sounds strange or complex and it would be a great chance to fix it at the moment.

How Google algorithm mimics humans?

It is very interesting that Google is capable of thinking and acting like a human in the present. Even a couple of years ago you would not even think about that. Google mimic the humans by analyzing their action and knowing what they are looking for throughout the years. Considering that, if the content contains too many repetitive words, too complex sentences, or too long paragraphs, it would not be highlighted by Google.

Test Your Website Issues

You can quickly analyze your site

Screpy Divider