Information has a leading role in the age of linguistic technology. Confidence in correct understanding information by other people is extremely important for everybody now - from primary school teacher to CEOs. There`s a property of text information, that enables us to assess its difficulty for the different groups of people. It`s readability. According to G. McLaughlin, readability is “the degree to which a given class of people find certain reading matter compelling and comprehensible”. Different methods of predicting the difficulty level of the text were included in readability formulas that were wide used in different researches. Now there is an ability to improve these formulas and to configure them for definite language. The research shows that different formulas are more relevant for various genres of text. Every method has to be tested on different text clusters and the results should be comparable to understand.