Readability checker
Score your writing with four formulas that disagree with each other.
Free, no signup, and it runs entirely in your browser.
Add at least 30 words. Below that these formulas swing wildly on a single long sentence, so a score would be worse than none.
About this tool
Readability formulas count syllables and sentence length; none of them can tell whether a sentence makes sense. What they are genuinely good at is catching drift — the paragraph where the sentences got longer and the words got Latinate without you noticing. Four are shown rather than one because they measure different things, and the spread between them is the actual signal.
- Coleman–Liau counts letters per word while Gunning Fog counts words of three or more syllables. Text heavy with long simple words scores very differently under each, and a wide spread usually means unusual vocabulary rather than difficult ideas.
- Grade 8 to 10 suits a general audience. Lower is not automatically better — writing everything at grade 5 makes complex subjects longer and vaguer, not clearer.
- Nothing under 30 words is scored. Below that a single long sentence swings every formula, and a confident wrong number is worse than no number.
- These formulas were built for English prose. Code blocks, tables and lists distort them, so score the prose on its own.
Questions
- What is a good Flesch Reading Ease score?
- 60 to 70 is plain English and suits most web writing. Above 80 is simple enough for a wide audience; below 50 is heavy going outside a technical readership.
- Why do the four formulas disagree?
- They measure different proxies for difficulty. Coleman–Liau uses letters per word, Gunning Fog and SMOG count polysyllabic words, Flesch–Kincaid uses syllables per word. Unusual vocabulary makes them diverge.
- Does readability affect SEO?
- Not as a ranking factor. It affects whether people finish reading, which affects the behaviour that search engines can measure.