Readability Score Checker
Check the Flesch Reading Ease and Flesch-Kincaid Grade Level of any English text, with live word, sentence, and syllable counts — runs 100% in your browser with no upload.
🔒 Scored entirely in your browser — nothing is uploaded. Tuned for English text.
Measure how easy your writing is to read
Paste any article, email, or essay and instantly see two standard readability scores. The Flesch Reading Ease runs from about 0 to 100 — higher means easier, where 60–70 is plain English and scores above 90 read like a children's book. The Flesch-Kincaid Grade Level translates the same data into a U.S. school grade, so a result of 8 means roughly an eighth-grade reading level. Both update live as you type, the Reading Ease score is also labelled with its standard difficulty band — from Very easy to Very difficult — and the underlying word, sentence, and syllable counts the formulas are built on are shown too. Use it to simplify dense paragraphs, hit a target reading level for a wider audience, or compare drafts side by side.
How the scores are calculated
Sentences are detected by runs of ., !, and ?; words are matched as runs of letters, digits, or underscores; and syllables use a vowel-group heuristic — each cluster of vowels counts once, a silent trailing e is dropped, and every word counts at least one syllable. From those, Reading Ease is 206.835 − 1.015 × (words ÷ sentences) − 84.6 × (syllables ÷ words) and the Grade Level is 0.39 × (words ÷ sentences) + 11.8 × (syllables ÷ words) − 15.59. The syllable step is a heuristic, so unusual spellings can be off by one, but the scores are stable and reproducible for everyday English prose.
Frequently asked questions
What is a good Flesch Reading Ease score?
For a general audience, aim for 60 or above — that maps to plain, easily readable English around an eighth-grade level. Scores from 30 to 50 are fairly difficult and typical of academic or technical writing, while scores above 80 are very easy and suit broad public content.
Why does the grade level sometimes look negative or very low?
The Flesch-Kincaid formula is math, not a floor at zero. Very short, simple sentences with mostly one-syllable words can produce a grade near or below zero. That just means the text is extremely easy to read; it is expected for sentences like "The cat sat."
Is my text uploaded anywhere?
No. All scoring happens locally in your browser using JavaScript — your text never leaves your device and nothing is sent to a server.