Readability Score Checker

Which formula to trust:

• ·Flesch-Kincaid: Best all-around for standard web content. Most widely referenced.
• ·Gunning Fog: Best for identifying technical jargon and complex vocabulary.
• ·Coleman-Liau: Best for content with many unusual words or industry terminology.
• ·SMOG: Best for healthcare, government, and public-facing documents where comprehension is safety-critical.
• ·ARI: Best automated measure — works well on varied content types.

When scores diverge:

If Gunning Fog is significantly higher than Flesch-Kincaid, your sentences are short but your word choice is technical. Focus on vocabulary simplification. If Flesch-Kincaid is high but Gunning Fog is moderate, your sentences are too long. Focus on sentence splitting.

Target ranges by content type:

• ·General web copy: Grade 6–8 average
• ·Email marketing: Grade 6–7
• ·Healthcare: Grade 6 or below (patient materials standard)
• ·Legal: Grade 8–12 (accessible legal writing benchmark)

Readability score checker vs Hemingway Editor:

Hemingway Editor is a writing tool that highlights complex sentences in real time as you write. This checker is an analysis tool that gives you quantitative scores across five validated formulas. Use Hemingway during drafting for real-time feedback, and this checker for final validation with precise formula scores.

Readability score vs content quality:

Readability scores measure mechanical complexity — sentence length and word complexity. They do not measure accuracy, usefulness, depth, or originality. High readability scores are not a substitute for high-quality content — they are a signal that your well-researched content is also accessible to your target audience.

Different readability formulas measure different dimensions of text complexity. Flesch-Kincaid emphasizes sentence length and syllables per word. Gunning Fog penalizes polysyllabic words directly. Coleman-Liau uses character counts — making it more reliable for texts with unusual vocabulary. SMOG (Simple Measure of Gobbledygook) focuses on polysyllabic word density in a sample. ARI (Automated Readability Index) uses character-to-word ratios.

Running multiple formulas simultaneously gives you a more robust picture than any single score. If all five formulas agree the text is at an 8th grade level, you can be confident in that assessment. If they diverge significantly — for example, Flesch-Kincaid says Grade 6 while Gunning Fog says Grade 12 — the text likely has short, simple sentences but a high density of technical vocabulary.

This checker runs all five formulas in parallel and presents a unified grade level average alongside the individual scores, so you can identify which specific dimension of your text is driving complexity and make targeted edits rather than rewriting everything.