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Readability checker
Paste your writing and see how hard it is to read, scored by the three standard formulas and translated into a school grade level — free, in your browser, with no account.
- Runs on your device
- Flesch, Kincaid and Fog
- Instant, no upload
Check your readability
Nothing is uploaded — your text stays in this tab
Flesch Reading Ease, Flesch–Kincaid Grade and the Gunning Fog Index
Three steps, about a minute
Paste your text
A paragraph is enough to get a signal; a full page gives a steadier score. Nothing leaves this tab.
Press Analyze
You get the three scores, the reading level they translate to, and the sentence and syllable counts behind them.
Fix the long sentences first
Sentence length moves every one of these scores more than word choice does. Split the worst offender and re-run.
Three scores, because one is easy to game
- Flesch Reading Ease. A 0 to 100 score where higher is easier. Most general writing aims for 60 to 70; anything under 30 reads like a legal contract.
- Flesch–Kincaid Grade. The same maths expressed as a US school grade, which is the number most style guides and government plain-language rules actually quote.
- Gunning Fog Index. Weights long words rather than syllables per word, so it catches jargon that the Flesch scores let through.
- The inputs are shown too. Words, sentences and syllables are printed alongside the scores, so you can see why a passage scored badly instead of guessing.
About this tool
What is a good readability score?
It depends on the audience. General web writing and journalism usually target a Flesch Reading Ease of 60 to 70, which is roughly an eighth to ninth grade level. Technical documentation for specialists can sit lower without being a problem. Plain-language rules for public-facing government writing often ask for grade 8 or below.
How is the score calculated?
Flesch Reading Ease is 206.835 minus 1.015 times the average sentence length minus 84.6 times the average syllables per word. Flesch–Kincaid Grade uses the same two inputs weighted differently. Gunning Fog uses average sentence length plus the percentage of words with three or more syllables.
Why did my score change when I only moved a full stop?
Because sentence length is the heaviest input in all three formulas. Splitting one forty-word sentence into two twenty-word sentences can move the grade level by a full year without changing a single word.
Does a good score mean the writing is good?
No. These formulas count syllables and sentence lengths — they cannot tell whether an argument holds together, whether the tone fits, or whether the facts are right. Treat a bad score as a prompt to look at a passage, not as a verdict.
Does it work on languages other than English?
The formulas were built for English and their syllable assumptions do not transfer. You will get a number for text in another language, but it will not mean what it claims. For counting words in Hindi or English, the word counter is the right tool.
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Your text, your device
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