Readability Analyzer
Flesch Reading Ease, Flesch-Kincaid grade level, and long-sentence flagging — because plain language is accessibility. Runs entirely in your browser.
How to use this tool
- Paste your text — an article, product copy, an email, documentation.
- Read the Flesch Reading Ease score and grade level, plus the sentences flagged as long.
- Revise the flagged sentences and watch the scores move as you edit.
How it works
Flesch Reading Ease scores 0–100 from average sentence length and average syllables per word (206.835 − 1.015·(words/sentences) − 84.6·(syllables/words)); higher is easier, with 60–70 corresponding to plain language most adults read comfortably. Flesch-Kincaid converts the same inputs to a US school-grade level. Syllables are estimated with a heuristic (counting vowel groups), so treat scores as a strong guide, not a decimal-precise measurement.
Plain language is an accessibility issue, not a style preference: WCAG's reading-level criterion targets content readable at a lower-secondary level, and readable text helps people with cognitive and learning disabilities, non-native speakers, and everyone reading in a hurry — which is everyone. The two biggest levers are almost always shorter sentences and shorter words.
Sources & references
Content last reviewed: July 2026.
Frequently asked questions
What's a good Flesch Reading Ease score?
60–70 for general audiences (roughly 8th–9th grade). News wires aim near 60; popular fiction runs 70–90; academic prose often scores below 30 — which is why nobody enjoys reading it.
What grade level should web content target?
Around 8th grade for general audiences — the level WCAG's reading-level criterion (lower secondary education) points to. Specialist audiences tolerate more, but even experts prefer clear prose.
How accurate are the scores?
The formulas are exact; the syllable counting is a well-behaved heuristic (English spelling makes perfect syllable counting genuinely hard). Scores are typically within a grade of hand calculation — right for guiding revision, wrong for passing regulatory thresholds by 0.1.