Readability Checker
Paste English text to score it with six established readability formulas and see which sentences make it hard to read. Scores are estimates based on sentence length, word length and syllables — useful for comparing drafts, not for grading writing.
How to use the Readability Checker
Paste your text
Body copy works best. Headings, lists and navigation text can distort scores.
Read the consensus grade
The average of the grade-level formulas gives a quick overall picture.
Open the hardest sentences
They're ranked by length and complex words, so you know where to start.
Edit and compare
Scores update as you type, so you can see the effect of each change.
What it checks
- Flesch Reading Ease
- 0–100; higher is easier. Based on sentence length and syllables per word.
- Flesch-Kincaid Grade
- The US school grade level the text roughly corresponds to.
- Gunning Fog
- Grade level based on sentence length and the share of words with three or more syllables.
- SMOG
- Grade estimate from polysyllabic words; most reliable with 30+ sentences.
- Coleman-Liau and ARI
- Grade estimates based on characters per word rather than syllables.
- Difficulty drivers
- Complex-word share, average sentence length, long sentences and passive-voice patterns, with the hardest sentences listed.
Interpreting the results
Each formula is shown with its score and a plain-English interpretation. Grade levels around 7–9 correspond to text most adults read comfortably; above 12, text reads as academic or technical. A Flesch Reading Ease of 60–70 is roughly “plain English”.
The formulas disagree with each other because they measure different things: syllables, characters, or polysyllabic words. That's why a consensus grade is shown alongside them. All syllable counts come from a heuristic, so scores are estimates — reliable for comparing versions of the same text, less so as absolute measurements.
Detected marks facts read directly from what you provided. Guidance marks general recommendations based on those facts — rules of thumb, not guarantees or search engine requirements.
Practical guidance
Readability formulas reward short sentences and short words. That's usually good advice for web copy, but not always: technical audiences expect technical terms, and splitting every sentence can make text choppy. Aim for a level that suits your readers, then use the hardest-sentences list to fix the worst offenders rather than rewriting everything.
The quickest improvements are almost always the same: break sentences over about 25 words in two, replace a vague phrase with a specific one, and turn passive constructions into active ones where it reads better. The passive-voice count uses a simple pattern (“was/were/been … -ed”), so treat it as a pointer, not a verdict.
Readable content matters when you're earning or placing links. Editors accept clear guest posts more readily, and a readable article is a better home for a link — see guest posting and what makes a quality backlink. For length and structure, use the Word Counter & Content Analyzer.
Limitations
- The formulas were designed for English. Scores for other languages aren't meaningful.
- Syllables are counted with a heuristic, so individual words can be miscounted.
- Formulas measure surface features. They can't tell whether text is accurate, well organised or suited to its audience.
- Very short texts (a few sentences) produce unstable scores.
Frequently asked questions
Which readability score should I use?
Flesch Reading Ease is the most widely recognised. For a grade level, look at the consensus of several formulas rather than any single one.
What grade level should web content aim for?
It depends on your audience. Many style guides suggest around grade 8 for general audiences; specialist content can reasonably be higher.
Does readability affect rankings?
There's no evidence search engines use these formulas directly. Readable content is easier for people to use, which is reason enough.
Is my text uploaded?
No. It's analysed in your browser.
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