Readability formulas are used in many different types of text analysis:

• Pharmaceutical manufacturers must formulate package inserts for medicines in a comprehensible way; this is required by the EU Commission.
• SEO (search engine optimising): The page ranking in search engines is strongly influenced by comprehensibility: mainly by word and sentence length. Both are part of readability formulas. The more comprehensible a text is, the higher it appears in the search results.
• Publishers: Especially textbooks, scientific and other non-fictional literature should be comprehensible. Publishers can see if and where texts can be improved and thus become more understandable.
• Website developers: Websites can be analysed to expand their readership and generate more clicks.
• Technical documentation: It must be written in a way that is as understandable as possible.
• Universities and other academic users: Whether mass media content, fictional texts or style analyses - these can be analysed. The text size can be arbitrary: Paragraphs, pages or whole books.