Readability Score Checker
Paste any text to get three industry-standard readability scores instantly: Flesch-Kincaid Grade Level, Flesch Reading Ease, and Gunning Fog Index. Color-coded results show your target audience at a glance. Every calculation runs in your browser — no text is ever uploaded anywhere.
Why Use This Readability Checker?
The readability score checker runs three industry-standard algorithms — Flesch-Kincaid Grade Level, Flesch Reading Ease, and Gunning Fog Index — simultaneously, using client-side JavaScript syllable counting and sentence analysis. All three metrics recalculate in real time as you type or paste text. Nothing is sent to a server; V8 handles the entire analysis pipeline in your browser tab. Use it to calibrate blog posts for a general audience, verify that legal copy meets plain-language standards, or check whether a student essay lands at the expected grade level.
Flesch-Kincaid Grade Level: Computes the U.S. school grade required to understand your text using the formula 0.39 × (words ÷ sentences) + 11.8 × (syllables ÷ words) − 15.59. A score of 8 means an 8th-grader can read it. Target 6–9 for most web content.
Flesch Reading Ease: Returns a 0–100 score where higher is easier — 90+ is children's content, 60–70 is standard web prose, below 30 signals academic-level complexity. Formula: 206.835 − 1.015 × (words ÷ sentences) − 84.6 × (syllables ÷ words).
Gunning Fog Index: Penalizes complex words (3+ syllables) using the formula 0.4 × (avg words/sentence + 100 × complex words ÷ total words). More sensitive to vocabulary choices than sentence length — useful for identifying jargon in legal, medical, or technical writing.
Color-Coded Difficulty Bands: Each score card shows a green-to-red band (Very Easy → Graduate Level) so you can assess readability at a glance without memorizing score ranges or looking up conversion tables.
Raw Stats Breakdown: Alongside the three scores, the tool surfaces word count, sentence count, total syllables, average words per sentence, and complex word count — the exact inputs that feed the formulas, so you can pinpoint which sentences or word choices are pushing up your grade level.
How to Check Your Readability Score
- 1
Paste your text into the input area. You can paste a blog post, email, essay, product description, or any prose — the tool handles everything from a single sentence to a full chapter.
- 2
Read the three score cards that appear below. Flesch-Kincaid Grade and Gunning Fog are grade-level estimates — lower means more accessible. Flesch Reading Ease is the inverse — higher scores mean easier reading.
- 3
Check the color band on each card. Green means your target audience can read it comfortably; yellow or orange signals room to simplify. For general web audiences, aim for FK Grade 6–8 and Reading Ease above 60.
- 4
Click Copy Summary to export all three scores plus the stats line — useful for pasting into a writing brief, editorial style guide, or client report.
Frequently Asked Questions
Also try the Word Counter for full readability stats and keyword density on the same text.
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