LIX Readability Checker

The Readability Index (LIX) indicates the readability of a text based on sentence length and individual word difficulty.

What is the Readability Index (LIX)?

The Readability Index (LIX) indicates how difficult or easy to read a text is. It takes into account the number of words per sentence, the length of individual words, and the number of syllables.

The shorter the sentences and words, the more readable the text is. Thus, LIX is also a useful indicator when it comes to simplifying and optimizing texts further.

How is the LIX determined?

Since the complexity of a text cannot be directly measured, and even experts find it difficult to make an accurate assessment, the following features are used to measure the Readability Index:

Sentence Length: The shorter the sentence and the fewer nested and subordinate clauses it has, the easier it is to comprehend.

Length of Individual Words: Short, clear, and concise words are more readable than long words, nominalizations, or compound words made up of multiple words.

Is readability a ranking factor?

Even though Readability Index may not (yet) be officially considered a ranking factor, good readability is enormously important. As the Google algorithm increasingly takes user-friendliness into account for evaluation, easily understandable and informative content becomes crucial.

Moreover, it is now more important than ever to write for people rather than search engines, making understandable and fluently readable text advantageous. It is not advisable to cram in an abundance of unnecessary keywords, which could degrade readability.

How does the LIX Readability Checker work?

The principle of the Readability Checker is simple: Just enter or paste the text to be checked into the field to instantly calculate and display the Readability Index.

It uses the popular formula by Björnsson (originally known as Läsbarhetindex in Swedish), which analyzes the LIX based on criteria such as word and sentence length as well as the number of words and syllables in relation to the text quantity.

Which Readability Values are distinguished?

The higher the Readability Index, the more difficult the language of the text. The following values indicate the difficulty level of the text according to the LIX and also suggest the corresponding type of text:

Below 40: Children's and young adult literature, which has a very low difficulty level.

40 to 50: Fiction, with a difficulty level in the lower mid-range.

50 to 60: Non-fiction with a medium to high difficulty level.

Above 60: Technical literature, with a difficult to very difficult readability.

Limitations of the Readability Index

The Readability Index is based "only" on a mathematical formula, which calculates the text based on sentence and word length in relation to the text quantity. There are certain limitations, as a long sentence can be easy to read if, for example, it consists of enumerations. On the other hand, a simple text can be difficult to read if it describes content unfamiliar to the reader.

While the calculation of the Readability Index is suitable for an initial assessment of the difficulty level of a text, it doesn't cover all objective and subjective complexity features.

Use LIX Readability Checker, Perform Text Analysis Online

Readability is crucial for texts on the web. Only with high readability are they easily understandable and able to inform quickly and vividly. Experience also shows that texts with good readability rank better. Therefore, when it comes to search engine optimization, it is recommended to use a Readability Checker and check your own text with it.

Use our LIX Readability Checker and find out how readable your text is right away.