What readability scores does this tool calculate?

This tool calculates six industry-standard scores: Flesch Reading Ease (0–100, higher = easier), Flesch-Kincaid Grade Level, Gunning Fog Index, SMOG Index, Coleman-Liau Index, and the Automated Readability Index (ARI). Each formula weights sentence length, word length, and syllable count differently — so you get a more complete picture than any single score alone.

What is a good Flesch Reading Ease score?

For most web content, aim for 60–70 (Standard, readable by ages 13+). News sites often target 60–70. Academic papers typically score below 30. Plain language guidelines recommend 60+. Blog posts and product descriptions perform best at 65–80. The higher the score, the broader the audience you can reach.

Why do different readability formulas give different grade levels?

Each formula was trained on different text corpora and weights factors differently. Flesch-Kincaid and SMOG focus heavily on syllables, Gunning Fog emphasizes long sentences and polysyllabic words, Coleman-Liau uses character counts instead of syllables, and ARI uses both characters and sentence length. Using multiple scores together is more reliable than trusting one alone.

Does this tool work for languages other than English?

The readability formulas here were designed for English text and rely on English syllabification rules. Results will be inaccurate for other languages. For non-English readability analysis, language-specific tools are more appropriate.

Is my text sent to a server when I use this tool?

No. All analysis happens entirely in your browser using JavaScript. Your text is never transmitted to any server, so sensitive documents, drafts, or proprietary content stays private.

可読性分析ツール

Flesch-Kincaid、Gunning Fog、SMOG、Coleman-Liau、ARIスコアでテキストの可読性を分析します。文章がどのレベルの読者を対象としているか確認できます。

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使い方

Flesch-Kincaid、Gunning Fog、SMOG、Coleman-Liau、ARIスコアでテキストの可読性を分析します。文章がどのレベルの読者を対象としているか確認できます。

1Paste or type your text into the input box. The analysis updates automatically as you type — no button to click.
2Check the Flesch Reading Ease score first. A score of 60–70 means your writing is comfortable for a general audience. Above 80 is very accessible; below 30 is academic or technical.
3Compare the grade-level scores (Flesch-Kincaid, Gunning Fog, SMOG, Coleman-Liau, ARI). If they cluster around grade 8–10, your writing suits most adults. Academic writing often reads at grade 12+.
4Look at the Text Statistics section. If your average sentence length is over 25 words, try breaking long sentences into two. Reducing complex words (3+ syllables) is the single biggest lever for improving readability scores.
5Try the Sample Text button to see how a well-written paragraph scores, then compare it against your own content.

主な機能

Six readability formulas — Flesch Ease, Flesch-Kincaid, Gunning Fog, SMOG, Coleman-Liau, ARI
Real-time analysis — scores update as you type with no button click required
Visual Flesch score bar — instantly shows whether text is easy, standard, or difficult
Full text statistics — word count, sentence count, syllable count, complex word count
100% private — text never leaves your browser

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Readability Score Guide — Write Content Anyone Can Read