Readability Checker
Score your writing with Flesch Reading Ease, Flesch-Kincaid Grade, and ARI, plus word, sentence, and syllable counts.
Processed locally in your browser — nothing is uploaded.
Readability Checker
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Paste some text to score its readability.
What the scores mean
- Flesch Reading Ease: 0–100 scale where higher is easier. 60–70 reads as plain English; below 30 suits academic writing.
- Flesch-Kincaid Grade: The US school grade needed to follow the text. 8 means an eighth-grader can read it comfortably.
- Automated Readability Index: Also a US grade level, but based on characters per word instead of syllables — stricter on long words.
About Readability Checker
Paste your draft and see three standard readability scores side by side: Flesch Reading Ease (higher is easier), Flesch-Kincaid Grade, and the Automated Readability Index (both expressed as US school grades). Supporting counts — words per sentence and syllables per word — show what is driving the score.
Everything is computed in your browser with a syllable-counting heuristic, so drafts never leave your machine.
Common uses
- Keep marketing copy in the plain-English band (60–70 Reading Ease)
- Check that documentation matches its audience's grade level
- Find out whether long sentences or long words are hurting a draft
Limitations
- English syllable counting is heuristic, so scores can differ by a point or two from other tools
- The formulas were designed for English prose — code, lists, and other languages score unreliably
Frequently asked questions
What is a good Flesch Reading Ease score?
60–70 reads as plain English that an eighth- or ninth-grader follows comfortably, which suits most web copy and marketing. Scores of 30–50 fit technical or academic audiences, and above 80 reads as very easy, conversational prose.
How is the Flesch-Kincaid Grade calculated?
As 0.39 times the average words per sentence, plus 11.8 times the average syllables per word, minus 15.59. The result maps to a US school grade, so shortening sentences or swapping long words for short ones directly lowers it.
What's the difference between Flesch-Kincaid and ARI?
Both output a US grade level, but Flesch-Kincaid measures word difficulty by syllables while the Automated Readability Index uses characters per word. ARI is therefore harsher on long words like "strengths" that have few syllables but many letters.
Why do different readability tools give different scores?
The formulas are standard, but their inputs aren't: tools count syllables with different heuristics and split sentences at different punctuation. Differences of a point or two are normal — track the trend of your own edits rather than comparing absolute scores across tools.
Are my drafts uploaded to score their readability?
No. Word, sentence, and syllable counts are all computed in your browser and the text is never transmitted or stored, so pre-publication manuscripts stay on your machine.