Six proven formulas
Flesch Reading Ease, Flesch-Kincaid, Gunning Fog, SMOG, Coleman-Liau and ARI, plus an average grade you can trust.
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Readability Checker Flesch Reading Ease, Grade Level & Writing Highlights
Paste your text to get a Flesch Reading Ease score and grade level from six proven formulas. This free readability checker also highlights long sentences, passive voice, adverbs and complex words, so you know exactly what to fix.
- 6 readability formulas
- Live highlights as you type
- Your text stays private
Readability checker
HighlightsClick a label to show or hide it
Start typing or paste text to see highlights here.
Flesch Reading Ease
–out of 100
Add some text
Higher scores are easier to read. Aim for 60 or more for a general audience.
Average grade level
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Waiting for textThe average of five grade formulas. Grade 9 or lower suits most readers on the web.
All readability scores
- Flesch Reading Ease–
- Flesch-Kincaid Grade–
- Gunning Fog Index–
- SMOG Index–
- Coleman-Liau Index–
- Automated Readability–
- Words
- 0
- Sentences
- 0
- Paragraphs
- 0
- Syllables
- 0
- Words per sentence
- 0
- Syllables per word
- 0
- Reading time
- 0 sec
- Speaking time
- 0 sec
Features
A readability checker that shows you what to fix
A score alone does not improve your writing. This tool pairs proven formulas with clear highlights, so every number comes with an action.
Writing highlights
Long and very long sentences, passive voice, adverbs and complex words are marked in colour right in your text.
Instant, as you type
Scores and highlights refresh while you edit, so you see each change make your text easier to read.
Plain-English suggestions
Get a short list of next steps, such as how many sentences to split or where passive voice slows readers down.
Full text statistics
Words, sentences, paragraphs, syllables, averages, plus reading and speaking time for talks and videos.
Private and autosaved
Your text never leaves your browser. It is saved on this device, so a refresh will not lose your draft.
How to use
How to use the readability checker
Paste your text
Copy in a blog post, email, essay or web page. Plain text works best.
Read your score
Check the Flesch Reading Ease score and the average grade level for your audience.
Fix the highlights
Split very long sentences, swap passive voice for active and trim needless adverbs.
Watch it improve
Scores update live as you edit. Copy the report when you are happy with the result.
Score guide
Flesch Reading Ease score chart
How to interpret your score. Most web content, marketing copy and news writing does best between 60 and 80.
| Score | Difficulty | School level |
|---|---|---|
| 90 to 100 | Very easy | 5th grade, about age 11 |
| 80 to 90 | Easy | 6th grade |
| 70 to 80 | Fairly easy | 7th grade |
| 60 to 70 | Plain English | 8th and 9th grade |
| 50 to 60 | Fairly difficult | 10th to 12th grade |
| 30 to 50 | Difficult | College |
| 0 to 30 | Very difficult | College graduate |
Formulas
The readability formulas explained
Each formula measures sentence length and word difficulty in a slightly different way, which is why we show all six and their average.
Flesch Reading Ease
Scores text from 0 to 100 using words per sentence and syllables per word. Higher means easier.
206.835 − 1.015(W/S) − 84.6(Sy/W)Flesch-Kincaid Grade
Turns the same inputs into a US school grade. It is widely used in education and government writing.
0.39(W/S) + 11.8(Sy/W) − 15.59Gunning Fog Index
Focuses on complex words with three or more syllables. A score of 12 suits a high-school graduate.
0.4[(W/S) + 100(complex/W)]SMOG Index
Counts polysyllabic words and is popular for health information. It works best on 30 or more sentences.
1.043√(poly × 30/S) + 3.1291Coleman-Liau Index
Uses letters instead of syllables, which makes it fast and consistent for computers to calculate.
0.0588L − 0.296S − 15.8Automated Readability
Also based on characters per word and words per sentence, originally designed for real-time typing checks.
4.71(C/W) + 0.5(W/S) − 21.43Tips
How to improve readability
Keep sentences short
Aim for an average of 15 to 20 words. Split any sentence that runs past 25.
Choose simple words
Say use instead of utilise and help instead of facilitate. Familiar words read faster.
Prefer active voice
The team reviewed the results is clearer than the results were reviewed by the team.
Cut weak adverbs
Replace very quickly ran with sprinted. Strong verbs carry meaning without extra words.
Use short paragraphs
Two to four sentences per paragraph give readers on phones room to breathe.
Read it out loud
If you run out of breath or stumble, the sentence needs work.
FAQ
Readability checker FAQ
What is a good readability score?
On the Flesch Reading Ease scale, 60 to 70 is plain English that most adults read comfortably, and anything above 60 suits most web content. As a grade level, aim for about grade 7 to 9 for a general audience, and lower for public information.
How is the Flesch Reading Ease score calculated?
The formula is 206.835 − 1.015 × (words ÷ sentences) − 84.6 × (syllables ÷ words). Longer sentences and longer words both lower the score, so shorter sentences and simpler words push it up.
What grade level should I write at?
For the general public, write at grade 8 or below. Many plain language guides recommend grade 6 to 8 for health, government and customer information, while technical or academic audiences can handle higher levels.
Why do the readability formulas give different results?
Each formula weighs different things. Flesch-Kincaid and SMOG count syllables, Gunning Fog counts complex words, and Coleman-Liau and ARI count letters. Looking at the average grade gives a more balanced view than any single formula.
How does the checker detect passive voice?
It looks for a form of the verb to be, such as is, was or were, followed by a past participle, as in was written or were made. This catches most passive sentences, but treat the highlights as prompts to review rather than strict errors.
Are adverbs always bad?
No. Adverbs are fine in moderation, but many can be removed or replaced with a stronger verb. For example, ran quickly can become sprinted, which is shorter and more vivid.
Is my text saved or shared?
Your text is analysed entirely in your browser and is never uploaded. It is autosaved in this browser so you do not lose a draft, and you can remove it at any time with the Clear button.
Does readability affect SEO?
Google has not said that readability scores are a direct ranking factor. However, clear, easy-to-scan writing helps visitors understand and stay on your page, which supports the goals of good SEO.
Write so everyone understands
Run every draft through the readability checker before you publish, and turn complex text into clear, confident writing. For more writing helpers, explore our free online tools.
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