Related tools
Why check readability?
Tune copy for your audience, teaching materials for a level band, or drafts before handoff—without sending text to a server.
Benefits
- Five metrics: common indices side by side.
- Instant: recalculates as you type or paste.
- Bands: Flesch Ease mapped to a plain-language label.
- Private: client-side only.
- Free: no account.
How it works
Counts and a syllable heuristic feed standard formulas. Outputs are estimates; syllables and sentence boundaries are imperfect.
What is computed
- Sentences: split on . ! ?; empty pieces dropped.
- Words: trim, whitespace tokens, non-empty.
- Syllables: per-word heuristic; complex word if syllables ≥ 3.
- ARI: uses characters excluding whitespace per word.
- Floors: Flesch clamped 0–100; other indices floored at 0.
When to use
Blog posts, help articles, internal comms, and classroom handouts aimed at a reading level.
Ideal use cases
- Web: simpler pages for broader reach.
- Education: check draft difficulty.
- Editing: before publishing.
- Comparison: two versions of the same message.
- QA: sanity-check dense paragraphs.
Facts
Indices were developed for English prose; marketing and legal text may behave oddly.
Key points
- Abbreviations and lists can skew sentence counts.
- Code or tables mixed in will distort word and syllable stats.
- SMOG is intended for longer samples; short text can be volatile.
- Different tools use slightly different syllable or sentence rules.
- Grade level is not the same as comprehension for every reader.
Best practices
Treat scores as signals, not verdicts.
Quality tips
- Clean to plain text before measuring.
- Compare revisions under the same paste.
- Pair with human review for tone and accuracy.
- For policy or medical copy, follow organizational standards.
- Very short snippets produce noisy metrics.
When not to rely on it
- Non-English or mixed-script documents without adaptation.
- Regulatory filings that specify a different methodology.
- Poetry, dialogue-only scripts, or heavy jargon without context.
Limitations and compatibility
English-oriented formulas; syllable heuristic; requires JavaScript.
Readability scoring runs fully in your browser with no server upload; all scores and difficulty bands update instantly as text changes.
Frequently asked questions
Is the readability checker free?
Yes. Analysis runs in your browser with no registration or upload.
Which formulas are used?
Standard textbook forms of Flesch Reading Ease, Flesch-Kincaid Grade Level, Gunning Fog, SMOG, and ARI using this page’s sentence, word, syllable, and character counts.
How are syllables estimated?
A lightweight English-oriented heuristic per word, not a dictionary. Counts may differ from linguistic syllabification.
What is Flesch Reading Ease?
A 0–100 score (here clamped after calculation). Higher values indicate easier reading for typical English prose interpretations.
Can I use this for non-English text?
Formulas assume English-like patterns; results for other languages are unreliable.
Is my text secure?
Yes. Processing stays on your device.