Readability Checker
Score your text against the classic Flesch, Flesch-Kincaid and Gunning Fog formulas. See your reading age, grade level and which words are slowing readers down — all in your browser.
Quick answer: Score your text against the classic Flesch, Flesch-Kincaid and Gunning Fog formulas. See your reading age, grade level and which words are slowing readers down — all in your browser.
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Frequently asked questions
- What does Flesch Reading Ease measure?
- It's a 0–100 score: higher means easier. 60–70 is plain English suited to most adults; under 30 is academic or technical writing.
- What's a Flesch-Kincaid Grade Level?
- A US-school grade. A score of 8 means an 8th-grader (about age 13) should be able to read the text. Most consumer writing aims for grade 6–9.
- What's the Gunning Fog Index?
- Another grade-level estimate, but it specifically penalises 'complex' words (3+ syllables). Useful when your text is grammatically simple but jargon-heavy.
- Why do the three scores disagree?
- Each formula weights word length, sentence length and complexity differently. Treat them as a triangulation, not a definitive grade — if all three agree your text is hard, it probably is.
- Is this exactly the same scoring Word and Hemingway use?
- It uses the same published formulas. Tiny differences come from how each tool counts syllables and detects sentence boundaries — our heuristic matches MS Word within a point on most prose.
- What reading age should I aim for?
- It depends. Marketing copy: 11–13. News writing: ~14. Help docs: 13–15. Internal corporate writing usually scores 16+ — and shouldn't.
- Does it work for languages other than English?
- No — the formulas are English-specific. Other languages need their own readability indices (LIX, SMOG-Spanish, etc.).
- Is my text uploaded?
- No. All counting happens in your browser. The text never leaves your device — there's no AI call, no server hop.
- How does it count syllables?
- It counts vowel groups, drops trailing silent 'e', and floors at one syllable per word. It's an estimate — phonetic dictionaries are more precise but much slower; the heuristic is accurate enough for ranking.
- How long can my text be?
- There's no fixed limit. Very long inputs (a whole book) might briefly slow your browser as it walks every word, but it'll still finish.