Text / Writing
Readability Checker (Flesch Reading Ease)
Score English text with the Flesch reading ease and Flesch–Kincaid grade level, with average sentence length, the share of long words, and the longest sentences listed.
Readability Checker (Flesch Reading Ease): Flesch reading ease = 206.835 − 1.015 × words per sentence − 84.6 × syllables per word, so short sentences and short words score high; 60 to 70 is plain English. The Flesch–Kincaid grade level turns the same counts into a US school grade: 0.39 × words per sentence + 11.8 × syllables per word − 15.59. Syllables are counted by English spelling rules, which agree with a pronouncing dictionary for about nine words in ten and are within one for nearly all. Runs 100% locally in your browser with zero server file uploads.
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The formulas were made for English and count syllables by rule, so scores are estimates; they do not suit other languages. Aim for 60 or more for a general audience.
Score bands
90–100: very easy, read by an 11-year-old. 60–70: plain English, understood by 13- to 15-year-olds. 30–50: difficult, college level. 0–30: very difficult, best understood by university graduates. Popular magazines tend to score 60 to 70; academic papers below 30.
To see which words dominate the text, use the word frequency counter; for its length in pages, words to pages.
Limits of the formulas
The formulas measure length, not meaning: a short sentence of rare words, or a clear explanation that needs technical terms, can score unfairly. Use the score to find long sentences, then judge the text by reading it.
How to use it
- Paste your English text.
- Read the Flesch reading ease (higher is easier) and the US grade level.
- Shorten the long sentences listed and re-check.
Privacy & limitations
Your text stays in your browser.
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Frequently asked questions
What score should I aim for?
For a general audience, 60 or higher, about grade 8 to 9. Government and health information often aims for 70 or more; legal and academic writing often scores below 30.
Does it work for other languages?
No: the constants were fitted to English, where words have fewer syllables than in many languages. Other languages have their own formulas, such as Fernández Huerta for Spanish.
How do I raise the score?
Split long sentences, use shorter everyday words, and prefer the active voice; the longest sentences are listed so you can start there.
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