About the Readability Score Checker
Readability Score Checker measures how hard your English text is to read using six well-known formulas. Paste your writing and you get the Flesch reading ease score, the Flesch-Kincaid grade level, the Gunning fog index, the SMOG index, the Coleman-Liau index and the Automated readability index, plus an average grade. It also shows the word and sentence counts, average sentence length, reading time at 238 words a minute, speaking time at 130 words a minute and your three longest sentences, which are the best place to start editing. The scores are estimates from simple counting, and they measure sentence and word length rather than whether the writing is clear, correct or interesting.
Updated September 2026
How to use the Readability Score Checker
- 1Type or paste your English text, or press Try a sample.
- 2Read the Flesch reading ease score and the average grade level.
- 3Check the longest sentences and shorten or split them.
- 4Edit and watch the scores update as you type.
What readability scores measure
Readability formulas look at two things: how long your sentences are and how long your words are. Long sentences with long words are harder to follow than short sentences with short words, so the formulas turn those counts into a score or a school grade. They don't understand meaning, so a text can score well and still be confusing, or score poorly and still be perfect for its audience.
The tool counts words, sentences and syllables. Syllables are estimated with a simple rule and are sometimes wrong, for example for words like create. Sentence ends are found from full stops, question marks and exclamation marks, so an abbreviation such as Mr. is counted as a sentence end. That is a known limit.
Flesch reading ease and grade level
Flesch reading ease gives a number, usually between 0 and 100, where higher means easier. Around 60 to 70 is plain English. The Flesch-Kincaid grade level uses the same ingredients to give a school grade instead. A text scoring 8 can be followed by someone with about eight years of school. Both formulas reward short sentences and short words.
Gunning fog, SMOG, Coleman-Liau and ARI
Short texts under 30 words give unreliable scores, so the tool adds a warning.
- Gunning fog: sentence length plus the share of long words with three or more syllables.
- SMOG: based on how many long words appear in the sentences, and often used for health information.
- Coleman-Liau: uses letters per word and sentences per 100 words, so it needs no syllable counting.
- ARI (Automated readability index): uses characters per word and words per sentence.
- The average grade is the mean of Flesch-Kincaid, Gunning fog, SMOG, Coleman-Liau and ARI.
Simple ways to raise your score
Aim to write for your reader, not for a number. For counting words and characters, see Word Counter and Character Counter, and to see which words you repeat, use Keyword Density Checker. Your text is analysed in your browser and isn't uploaded.
- Split sentences longer than 20 words into two.
- Prefer short, familiar words: use instead of utilise, help instead of facilitate.
- Cut filler such as very, really and in order to.
- Use active voice: the team fixed the bug, not the bug was fixed by the team.
- Read your text aloud. Wherever you run out of breath, add a full stop.
Features
- Six readability formulas and an average grade
- Reading time and speaking time
- Words, sentences, syllables and letters
- Your three longest sentences highlighted
- Live results as you type
- Private: your text stays in your browser
Frequently asked questions
What is a good Flesch reading ease score?
Scores run from about 0 to 100, and higher is easier. A score of 60 to 70 is called plain English and suits most general readers. Scores of 80 or more are very easy to read, and scores under 30 are very hard, like academic or legal writing.
What is the Flesch-Kincaid grade level?
It converts sentence length and syllables per word into a US school grade. A result of 8 means a reader with about eight years of schooling should follow the text. The tool shows it alongside four other grade formulas and their average.
Does readability affect SEO?
Google does not use a readability score as a ranking factor. But clear writing helps visitors understand your page and stay on it, which is why the numbers are useful as a writing aid, not as a target to chase.
How can I make my writing easier to read?
Use shorter sentences, everyday words and active verbs. Split a long sentence into two, replace a long word with a shorter one where it means the same thing and cut words that add nothing. The longest sentences list shows where to begin.
How is reading time calculated?
Reading time divides your word count by 238 words per minute, an average for silent reading. Speaking time uses 130 words per minute, a typical pace for reading aloud. Real speeds vary from person to person.
Why do different tools give different scores?
Each tool guesses syllables and sentence boundaries in its own way. Abbreviations like Mr. can end a sentence early and numbers count as words. Small differences are normal, so compare scores from the same tool over time.
Does it work in other languages?
No. The formulas and the syllable rules are designed for English. Text in another language will give scores that are not meaningful.