Tukuk-OS📖 Readability Checker
ℹ️ What this tool does & how it works
Rudolf Flesch's 1948 insight was that readability is arithmetic: sentences and words predict how hard a text reads — 206.835 − 1.015×(words per sentence) − 84.6×(syllables per word). Above 90 reads like a children's book, 60–70 like the news you are writing, below 30 like a journal. This page counts your words, sentences and syllables (heuristic vowel-group counter, same one the classics use) and runs the two published formulas out loud.
What the score can and cannot tell you
Flesch measures rhythm — sentence length and word length — nothing about whether the text is true, clear or kind to the reader. A list of short simple nonsense scores 100+; a perfectly clear technical definition with three long words can read "difficult". Use it as a smoke alarm for runaway sentences, not as a writing trophy: the counter on this page also counts hyphenated compounds and possessives as one word and treats silent trailing -e as unheard, the same conventions the original 1948 implementation documented.