What is a readability score checker?
Readability formulas turn two simple measurements into a number: how long your sentences are, and how many syllables your words have. Long sentences full of long words score as harder. Short sentences with short words score as easier. A readability score checker does that arithmetic for you.
This readability score checker gives you four results after you click Analyze Readability: Flesch Reading Ease (0 to 100, higher is easier), Flesch-Kincaid Grade (a US school grade), Gunning Fog Index and a SMOG-style index. You also get an overall label such as Easy or Difficult, a bar showing where the Flesch score falls, and statistics like average words per sentence and the share of complex words with three or more syllables.
Know what these numbers are. They are estimates built for English prose. Syllables are counted by a rule of thumb, so the tool will miscount some words. The SMOG figure is an approximation, not the original formula. Scores say nothing about accuracy, tone or whether readers will find your page useful. Use them as a nudge to shorten sentences, not as a goal.
How to check the readability of your text
- Paste your article or paragraph into Paste Your Content. A live line below shows words, sentences and syllables as you type.
- Choose a Target Audience: General Public, Blog / Web Content, Academic / Professional or Children / Young Adults.
- Click Analyze Readability. You need at least 10 words, and the tool suggests 100 or more for steadier scores.
- Read the four score cards and the Overall Readability label.
- Check Text Statistics for average sentence length, syllables per word and complex word share.
- Follow the Recommendations, edit your text, and analyze again.
What this tool calculates
Four formulas
Flesch Reading Ease, Flesch-Kincaid Grade Level, Gunning Fog Index and a SMOG-style index, calculated from the same counts.
Overall label and grade badge
A label from Very Easy to Very Difficult is based on Flesch Reading Ease, with a badge showing the rounded Flesch-Kincaid grade.
Flesch bar
A colour bar marks the score from 0 (very hard) to 100 (very easy): green at 60 and above, amber from 30, red below.
Text statistics
Word, sentence and paragraph counts, average words per sentence, average syllables per word and complex word share.
Audience target
The recommendations note a target Flesch score: 40 or more for academic text, 65 or more for the other options.
Plain suggestions
Warnings appear for sentences averaging over 20 words, more than 15% complex words, or too few paragraphs in longer text.
Who uses it, and for what
- Bloggers and content writers. Check a draft before publishing. A Flesch score in the 60s generally reads as plain English.
- Marketers writing landing pages. See whether your product copy is heavy with long sentences, then tighten it.
- Teachers and course creators. Estimate the US grade level of a reading passage or handout.
- Editors in an SEO workflow. Run the same draft through the Keyword Density Checker and the Word Counter, then review how it reads.
Tips for reading the scores
- Paste at least 100 words. Very short samples swing a lot, because one long sentence changes the average.
- Paste plain sentences. Lists, headings and code without full stops are treated as a single long sentence, which lowers the score.
- Separate paragraphs with a blank line, or the paragraph count will read as one.
- The Target Audience menu changes only the recommendation text. It does not change the four scores.
- Do not chase a perfect number. Replace long words with shorter ones only where the meaning stays the same.
- The tool is for English. Other languages need different formulas, so results will be unreliable.
Is it safe? Privacy and limits
The scores are computed in your browser. Your text is not uploaded or stored by this tool. Syllable counting is a heuristic, so exact numbers may differ from other calculators or from Microsoft Word. Treat the output as an estimate of reading ease, not a measure of quality, accuracy or search ranking. It is not an assessment for official educational or legal use.
Readability score checker FAQ
It is a number that estimates how easy a text is to read, based mostly on average sentence length and average word length. The Flesch Reading Ease score runs from 0 to 100, with higher meaning easier. Grade-level scores, like Flesch-Kincaid, express the same idea as the US school year needed to follow the text. These formulas ignore meaning, layout and the reader's background, so they are only a rough guide.
It calculates Flesch Reading Ease (206.835 minus 1.015 times average sentence length minus 84.6 times average syllables per word), Flesch-Kincaid Grade (0.39 times sentence length plus 11.8 times syllables per word minus 15.59), Gunning Fog (0.4 times the sum of sentence length and the percentage of complex words) and a SMOG-style value. The SMOG result is an approximation scaled to 30 sentences, not the original polysyllable count.
For general web content, 60 to 70 is often given as plain English, and higher is easier. This tool labels 70 and above as Very Easy, 60 to 69 as Easy, 50 to 59 as Fairly Easy, 30 to 49 as Difficult and below 30 as Very Difficult. Those labels are this tool's own bands. Technical or academic writing can reasonably score lower, and a score of 100 is not the aim.
Not directly as a ranking factor that Google has confirmed. But clear writing tends to keep readers on the page and helps them find answers, which matters for results that people click and use. Google's guidance asks for helpful content written for people. So use readability scores to find hard-to-read passages, not as a way to rank. Pair them with a check of titles in the SERP Preview Tool.
Tools differ in how they split sentences and count syllables. This one splits on full stops, question marks and exclamation marks, ignores very short fragments, and estimates syllables with a pattern rule that can be off for names and unusual words. Complex words also exclude words ending in -es or -ed. Small differences in these choices change the result by a few points. Compare scores from the same tool over time.
It changes only the recommendation note. It sets the Flesch target to 40 for Academic / Professional and 65 for General Public, Blog / Web Content and Children / Young Adults, and the note tells you your score against it. The four score cards and the overall label are the same whichever option you pick. Use it as a reminder of who you are writing for, not as a filter.
The tool needs at least 10 words to run, but 100 or more gives a more stable result. With a few sentences, one very long sentence can push the grade up several levels. For long articles, you can paste the whole text or analyse sections separately to find where it gets hard to read. Remember that headings and bullets without punctuation can be read as long sentences.
Not reliably. The formulas were designed for English, and the syllable counter only looks at the letters a to z with English-style vowel rules. Text in other languages, or with accented letters, will be counted wrongly and the scores will not mean much. Other languages have their own readability formulas. For English text, use the numbers as an estimate and revise by reading aloud.