readability

Readability is usually measured with formulas. The two most common are Flesch Reading Ease (a 0-100 scale, where higher means easier) and the related Flesch-Kincaid grade level (mapped to US school grades). Both estimate difficulty from sentence length and syllables per word, so they reward short sentences and plain vocabulary.

Google has repeatedly said it has no readability algorithm. John Mueller put it plainly: “we don’t have kind of the basic algorithms that just count words.” An Ahrefs study of 15,000 keywords found virtually zero correlation between Flesch Reading Ease and where a page ranks. So there is no magic score to chase and no grade level you have to hit.

Where readability does bite is indirectly. Google’s own helpful-content guidance asks whether content has “spelling or stylistic issues” and whether it “appears sloppy or hastily produced.” Copy that is hard to follow loses readers, earns fewer links, and does a worse job answering the query, all of which feed back into performance over time.

Write for your reader, not the score

Match the reading level to the audience and the topic. A consumer guide should read easily; a clinical or legal page can sit higher without being wrong. Practical wins: shorter sentences, one idea per paragraph, descriptive subheads, bullet lists, and swapping jargon for a plain word where you can. The same clarity that keeps humans reading also helps AI answer engines lift a clean passage and cite you.