WordieReadability Checker
Paste any English text and get six standard readability scores at once, with word, sentence and syllable counts and a list of the long words that make it harder to read.
Long and complex words
What does a readability checker measure?
A readability checker estimates how hard a text is to read from two surface features: how long the sentences are and how long the words are. Long sentences put more load on working memory, and long words tend to be rarer and more abstract. Every formula on this page combines those two signals in a slightly different way, which is why it shows six scores instead of one. If they roughly agree, you can trust the general picture.
This checker counts words, sentences and syllables in your browser. Syllables are estimated with an English rule set (vowel groups, silent final e, -ed and -es endings and common exceptions), which is accurate for most everyday words but can be off by one on unusual ones.
The readability formulas
In the formulas, W is words, S is sentences, Syl is syllables, L is letters per 100 words and S100 is sentences per 100 words.
- Flesch Reading Ease:
206.835 − 1.015 × (W/S) − 84.6 × (Syl/W). Higher is easier; most texts fall between 0 and 100. - Flesch–Kincaid Grade Level:
0.39 × (W/S) + 11.8 × (Syl/W) − 15.59. The result is a US school grade. See Flesch–Kincaid readability for its history. - Gunning Fog:
0.4 × [(W/S) + 100 × (complex words / W)]. Complex words have three or more syllables, not counting hyphenated words or words that only reach three syllables through -es, -ed or -ing. - SMOG:
1.0430 × √(polysyllables × 30 / S) + 3.1291. Polysyllables are all words of three or more syllables. - Coleman–Liau:
0.0588 × L − 0.296 × S100 − 15.8. Uses letters instead of syllables. - Automated Readability Index (ARI):
4.71 × (letters/W) + 0.5 × (W/S) − 21.43.
How to interpret your readability score
| Grade level | Typical text | Good for |
|---|---|---|
| Below 6 | Children's books, simple instructions | Beginner English learners, signs, UI copy |
| 6–9 | Popular fiction, most news, good web writing | General audiences, intermediate learners |
| 10–12 | Quality journalism, business reports | Educated adults, upper-intermediate learners |
| 13–16 | Textbooks, academic essays | University readers, advanced learners |
| 17+ | Research papers, legal contracts | Specialists |
For most web pages, emails and documentation, aim for a Flesch score of 60 or higher and a grade of 8 to 10. If you are choosing reading material as an English learner, readability is a useful first filter, but vocabulary matters more: check what share of the words you already know with the lexical coverage calculator.
Limitations of readability formulas
- They ignore meaning. Scrambling the words of a sentence leaves the score unchanged. Short words can still be rare ("ewe", "fief") and long words can be very familiar ("everybody").
- Sentence detection is approximate. Abbreviations such as "e.g." or "Dr." can be counted as sentence ends, and bullet lists without punctuation look like one long sentence.
- Short samples are noisy. A few sentences can swing the result. SMOG in particular was designed for samples of 30 sentences.
- English only. The constants were fitted to English texts and readers.
Use the scores to spot problems, then fix them by splitting long sentences and swapping needlessly long words, not by chasing a number.
Related reading
- Lexile measures and how they differ from grade levels
- Lexical density and lexical diversity
- How to improve your vocabulary for writing
- Graded readers for learners who need easier texts
How to use this tool
- Paste or type your English text into the box (the sample text shows how it works).
- Scores update as you type: check the Flesch Reading Ease and the average grade level first.
- Compare your score with the interpretation table to see who can read the text comfortably.
- Look at the long and complex words list and replace the ones a simpler word could do.
Frequently asked questions
What is a good Flesch Reading Ease score?
For general web content, 60 to 70 (plain English) is a common target. Scores above 70 are easy for most readers, while academic and legal texts often score below 30.
What is the difference between Flesch Reading Ease and Flesch-Kincaid Grade Level?
Both use average sentence length and syllables per word, but Reading Ease gives a 0 to 100 score where higher is easier, and Flesch-Kincaid converts the same inputs into a US school grade where lower is easier.
Why do different readability formulas give different grades?
Each formula weights different features. Flesch-Kincaid, Gunning Fog and SMOG rely on syllables, while Coleman-Liau and ARI count characters. A text full of short but rare words can look easy to one and harder to another.
Does this readability checker work for languages other than English?
Not reliably. The formulas and the syllable counter were designed for English. Other languages need their own adapted formulas.
Is my text uploaded anywhere?
No. The analysis runs entirely in your browser. Nothing you paste is sent to a server or saved.
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