Readability Checker
Check the Flesch Reading Ease and grade level of your text.
đ Runs entirely in your browser â nothing is uploaded.
âšī¸ Uses the Flesch Reading Ease and Flesch-Kincaid Grade Level formulas, with an approximate syllable counter.
How Readability Checker works
What formula does the readability checker use?
It calculates the Flesch Reading Ease score (206.835 minus 1.015 times average sentence length, minus 84.6 times average syllables per word) alongside the Flesch-Kincaid Grade Level (0.39 times average sentence length, plus 11.8 times average syllables per word, minus 15.59) - the two most widely used plain-language readability formulas. Syllables are estimated with a rule-based heuristic that strips silent endings and counts remaining vowel clusters, rather than looking each word up in a pronunciation dictionary.
When should I use it?
It is meant for checking whether a blog post, product description, or set of instructions is pitched at the right reading level for your audience - many style guides target an 8th-to-9th-grade Flesch-Kincaid level for general web content. It also quickly flags overly long, jargon-dense sentences before you publish.
How accurate is the syllable count?
The syllable counter is an approximation based on vowel-cluster patterns rather than a real pronunciation dictionary, so it can misjudge silent letters, diphthongs, or irregular words (it does guarantee at least one syllable per word so scores never break). Since both formulas depend on that estimate, treat the resulting grade level as a useful ballpark rather than an exact score; the whole calculation runs client-side in your browser.