Paste your text for instant Flesch, Flesch-Kincaid, Gunning Fog, SMOG and Coleman-Liau scores — plus a plain-English reading level. Find out who can actually read your writing.
Paste a paragraph or load the example to see all five readability scores.
Flesch Reading Ease, Flesch-Kincaid Grade, Gunning Fog, SMOG and Coleman-Liau — the standards editors and educators rely on.
Not just numbers — a clear label like "Easy (8th grade)" so you instantly know if your text fits your audience.
Scores recompute as you type, entirely in your browser. Your draft is never uploaded.
A readability score is an estimate of how much effort a reader needs to get through your writing — usually expressed as a U.S. school grade. A "grade 8" result doesn't mean your ideas are simplistic; it means a typical eighth-grader could follow the sentences without re-reading. That's the whole point. Plain prose isn't dumbed-down prose. It's writing that doesn't make people work harder than they have to.
Why bother measuring it? Because most of us write at our own reading level, not our audience's, and we rarely notice the drift. A sentence that feels crisp in your head can run forty words long on the page. A score gives you an outside opinion the moment you ask for it, so you can catch a paragraph that's quietly slid out of reach before a reader does — and bounces.
Every formula here is built on the same two intuitions: long sentences are harder to hold in mind, and long or many-syllabled words are harder to decode. They just weigh those ingredients differently. Flesch Reading Ease and Flesch-Kincaid Grade combine average sentence length with syllables per word. Gunning Fog and the SMOG Index lean on the share of "complex" words — three or more syllables. Coleman-Liau skips syllable counting entirely and uses characters per word instead, which makes it steadier on technical text where syllable rules get fuzzy.
This checker does that arithmetic live in your browser as you type. It splits your text into sentences and words, estimates syllables with a vowel-group heuristic that adjusts for silent endings, then runs all five equations and translates the headline number into a plain label. Nothing is uploaded — the math is light enough to run on the page itself, which is also why it can update on every keystroke without a round trip.
The people who paste text in here usually have a specific reader in mind and a reason to worry they've overshot:
Start with Flesch Reading Ease, the 0–100 score where higher is easier. For a broad public audience, 60 and up is the comfortable zone; plain-language work tends to aim for 70+. The four grade-level scores — Flesch-Kincaid, Gunning Fog, SMOG and Coleman-Liau — should cluster within a grade or two of each other. When they agree, trust the consensus and move on.
When they disagree, the gap is the interesting part. If Coleman-Liau reads higher than the syllable-based scores, you probably have a lot of long words rather than long sentences — domain jargon, say. If Gunning Fog spikes while sentence length looks fine, complex words are the culprit. That tells you what to fix, not just that something's off: shorten sentences when the syllable formulas run high, swap out heavy vocabulary when the complex-word formulas do.
These formulas count structure, not sense. They can't tell whether your argument holds, whether a sentence is ambiguous, or whether a short, simple line is also completely wrong. You can game any of them — chop every sentence in two and the grade drops while the writing gets choppier and worse. A good score is a green light to publish only after the meaning already works; it's never a substitute for reading the thing.
A couple of practical cautions. The scores wobble on very short text, so paste a full paragraph — ideally 100 words or more — before you read much into them. They also assume ordinary English prose: bullet lists, code blocks, headings and tables can distort the sentence count and throw the numbers off. And syllable estimation is a heuristic, so an unusual name or rare word can be off by one. Treat the result as a useful second opinion on effort, then trust your ear for everything it can't see.
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