Readability Score Checker
The Readability Score Checker analyzes any block of text and returns Flesch Reading Ease, Flesch-Kincaid Grade Level, Gunning Fog, SMOG, Coleman-Liau and the Automated Readability Index, with sentence, word and syllable counts. Long sentences are highlighted so you know exactly what to edit. Built for SEO specialists, content writers and developers who want to check copy without third-party accounts.
Your text
Scores update as you type. Each line break counts as a sentence end, so headings and list items are scored on their own.
Sentence lengths
Flesch Reading Ease
0 to 100, higher is easier. This reads at 8th to 9th grade level. 60 or more suits most web pages.
Grade levels
| Formula | Grade |
|---|---|
| Flesch-Kincaid GradeUS school grade from words per sentence and syllables per word. | 8.5 |
| Gunning FogYears of schooling, weighted by words of 3+ syllables (not names or -ed/-es/-ing forms). | 9.2 |
| SMOGPolysyllables per sentence. Designed for 30+ sentences, so treat short texts as rough. | 10.6 |
| Coleman-LiauLetters per word and sentences per 100 words; ignores syllables. | 10.1 |
| Automated Readability IndexCharacters per word and words per sentence. | 8.6 |
Average of the five: grade 9.4. Grades 6 to 9 suit general audiences; syllables are estimated, so expect small differences from other tools.
Longest sentences
- 47 wordsLong, winding sentences that pile up clauses, qualifications and technical terminology, especially when every other word carries three or four syllables, force readers to hold too much in their heads at once and make them far more likely to abandon the page before they reach your point.
- 14 wordsMost web copy should aim for a Flesch Reading Ease of 60 or higher.
- 14 wordsEdit the text in this box to see every score update as you type.
Flesch Reading Ease: 62.2
Flesch-Kincaid Grade: 8.5
Gunning Fog: 9.2
SMOG: 10.6
Coleman-Liau: 10.1
ARI: 8.6
Sentences: 7, words: 109, syllables: 166
Average sentence length: 15.6 wordsHow to use
- Paste your content into the text box. Every score updates as you type.
- Read the Flesch Reading Ease score and the grade levels from five formulas.
- Review the highlighted sentences over 25 words and the list of your longest sentences, then shorten or split them.
- Copy the scores to keep a record or share them with your team.
Why use this tool?
Frequently asked questions
What is the Readability Score Checker?
A free online tool that calculates six standard readability formulas for any text you paste in and highlights the long sentences that make it harder to read.
Which readability formulas does this tool use, and what scores should I aim for?
It calculates Flesch Reading Ease (0 to 100, where 60 to 70 suits general web content), Flesch-Kincaid Grade Level (target 6 to 8 for broad audiences), Gunning Fog, SMOG, Coleman-Liau and the Automated Readability Index, plus average words per sentence (aim for under 20). For a technical audience such as developers or medical professionals, a grade level of 10 to 12 and a lower Flesch score are acceptable. For landing pages and blog posts aimed at general consumers, aim for a Flesch Reading Ease above 60.
Why do my scores differ from other tools?
Every formula depends on syllable and sentence counts, and each tool estimates those slightly differently. This checker counts syllables with English pronunciation rules and treats each line break as a sentence end, so headings and list items are scored on their own. Compare scores from the same tool over time rather than across tools.
Is it free?
Yes, the Readability Score Checker is free with no signup required. It runs entirely in your browser, so nothing you paste is uploaded. Built by the Canvas Builder team.
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