What is Readability Score?

Analyze your text's readability using Flesch-Kincaid Grade Level, Gunning Fog Index, Coleman-Liau Index, and more. Get a clear grade level, difficulty rating, and suggestions to make your writing more accessible to your target audience.

Six standard formulas run at once: Flesch Reading Ease, Flesch-Kincaid Grade, Gunning Fog, Coleman-Liau, SMOG, and the Automated Readability Index. Each one weighs sentence length and word complexity differently, so seeing them side by side catches outliers — a single long paragraph or a bunch of jargon shows up as a spike on one of the indexes.

How to use

1. Paste or type your text into the editor (minimum 100 words recommended for accurate scores).
2. Review the readability scores across multiple indexes and the estimated grade level.
3. Download the full readability report or copy individual scores for your records.

When to use

• Trimming a blog draft so it reads at 8th-grade level instead of college.
• Checking corporate communications against an internal plain-language guideline.
• Comparing two drafts to confirm an edit actually made the writing simpler.

Result

A content marketer pastes a blog post draft (850 words). Flesch-Kincaid shows grade 11.2 — too complex for a general audience. They simplify sentences until reaching grade 7, ideal for web content.

FAQ

Which readability score should I actually pay attention to?

Flesch-Kincaid Grade is the most widely cited because it maps directly to US school grades. Use Flesch Reading Ease (0–100, higher is easier) for a quick sanity check, and compare it against Gunning Fog if your text has technical jargon — Fog penalises complex words heavily.

Why is my score worse than I expected?

Usually one of three things: sentences over 25 words, lots of three-syllable words, or sparse punctuation. Try splitting compound sentences, replacing latinate verbs with short Anglo-Saxon ones, and using full stops instead of semicolons.

How much text do I need for an accurate score?

At least 100 words, ideally a few full paragraphs. Under 100 the indexes swing wildly because one outlier sentence dominates the average. SMOG specifically asks for 30 sentences and gives unreliable readings on short passages.

Do these scores work for non-English text?

The formulas were calibrated on English and rely on English syllable patterns. They'll still compute a number for other languages but the grade-level mapping breaks down — use them as a relative comparison between two drafts in the same language, not as an absolute reading level.

Should I aim for the lowest possible grade level?

No. Match the audience. Web copy and news aim for grades 7–8, marketing landing pages 5–7, academic papers 12+, and legal writing usually 14–16. Going too simple sounds patronising; going too complex loses readers.

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