Measure readability with multiple established formulas, see where they agree, inspect the hardest sentences, review syllable counts, compare revisions, and understand which variables are moving the score—all locally in your browser.
9+ formulasSentence mapSyllable overridesBefore / after25 languages
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Formula validity matters. English grade formulas are shown as validated only for English. Character-based formulas may be displayed as structural estimates for some alphabetic languages, but CJK and Arabic are not forced through English formulas. Spanish, Italian and German receive language-specific formulas. Syllable-dependent results are estimates and can be corrected in Syllable Lab.
No accountNo AI rewriteLocal processingFormula transparencyManual syllable correction
Text to analyze
Paste an article, essay, email, report, policy, landing page, or academic passage.
No analysis
Words0—
Sentences0—
Syllables0estimated
Avg sentence0words
Long words07+ letters
Read time0m238 wpm
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Consensus grade
Analyze enough text to compare compatible grade-level formulas.
Target8–10—
Add text to calculate readability formulas.
No sentence analysis yet.
No word analysis yet.
Save a baseline, edit the text, then compare.
No score drivers yet.
Report exports use the current analysis. JSON includes raw metrics, formula results, target band and manual syllable overrides. CSV provides a compact formula table.
Interpretation: readability formulas estimate surface-level text difficulty from variables such as sentence length, word length, syllables and character counts. They do not measure factual accuracy, logical quality, accessibility for every reader, subject knowledge, or whether a passage is “good writing.” Use scores as diagnostics, not as a writing verdict.