Readability Checker
Paste your text and see how easy it is to read. You get the Flesch Reading Ease score and the Flesch-Kincaid grade level live, plus average sentence length, syllables per word, and a clear statement of what school grade can comfortably read your writing.
Typical target scores by content type
- Web copy, blog posts, product pages60–70
- Marketing, ads, email — broad consumer audience70+
- Academic and technical writing for experts30–50
Typical guidance, not rules — the right level is whatever your actual audience reads comfortably.
What the formulas actually measure
Both scores come from Rudolf Flesch's work in the 1940s and its US Navy revision in the 1970s, and both use exactly two ingredients: how long your sentences are (words per sentence) and how long your words are (syllables per word). Flesch Reading Ease is 206.835 − 1.015 × (words ÷ sentences) − 84.6 × (syllables ÷ words), reported on a 0–100 scale where higher is easier. Flesch-Kincaid Grade re-maps the same inputs onto US school grades: 0.39 × (words ÷ sentences) + 11.8 × (syllables ÷ words) − 15.59.
That means the formulas measure the surface of your prose, not the clarity of your ideas. A logically muddled text made of short common words scores beautifully; a crisp, well-organized argument full of necessary technical terms scores poorly. The scores correlate with reading difficulty across large samples — which is why they are embedded in everything from Word to US state insurance law — but for any single text they are a smoke detector, not a judge.
How to improve a score honestly
Two levers move the score, and used honestly both make real text better. First, sentence length: hunt for sentences carrying two or three ideas and give each idea its own sentence. Aim for an average of 15–20 words per sentence with plenty of variation — not a hard cap. Second, word length: prefer the common short word when it says the same thing ("use" over "utilize", "help" over "facilitate"), and keep the long word when it is the precise one.
The limit of this game is obvious once you see it: the formula cannot tell simplified prose from chopped prose. Five-word sentences all the way down will score in the 90s and read like a ransom note. Edit for the reader, then use the score to verify the trend — never the other way around.
More writing tools
Readability is built on syllables — the syllable counter uses the same engine and shows you the per-word breakdown behind these scores. The word counter adds keyword density and full text statistics, the character counter checks platform length limits, and the reading time calculator tells you how many minutes your text takes to read or speak.