Sentence Length Checker — Paste any text and see the word count of every sentence, the average and median sentence length, and a distribution chart that shows how your sentences stack up against the recommended 15–20 word range.
Analysis happens in your browser.
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Sentence Length Checkerとは？
Paste any text and see the word count of every sentence, the average and median sentence length, and a distribution chart that shows how your sentences stack up against the recommended 15–20 word range.
Sentences over 35 words are flagged for easy editing. The most common readability advice is "vary your sentence length," and this tool shows you whether you are doing that or not.
使い方
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Paste your text
Drop in an article, essay, email, or any block of prose you want to check.
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Read the headline numbers
Total sentences, average, median, and longest. If the average is over 25 words, your prose is dense; under 14, it may feel choppy.
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Fix any sentence over 35 words
The tool flags run-on candidates. Each one is shown in full so you can split it without losing context.
よくある質問
関連ガイド
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How to Count Words, Sentences, and Paragraphs (and Why Each Matters)
Three different counts, three different purposes. The formulas, the edge cases that trip people up, and the free tools that do it without uploading your text.
関連ツール
Sentence & Paragraph Counter
Count sentences, paragraphs, words, characters, and reading time all at once. Find your longest word and average sentence length.
文字数カウンター
テキストの単語・文字・文章・段落数をカウントします。無料、ブラウザで動作、アップロード不要。
Reading Time Calculator
Estimate how long it takes to read or speak a piece of text. Adjustable words-per-minute for fiction, non-fiction, or speech.
Character Counter
Count characters, words, lines, and UTF-8 bytes as you type.
Last reviewed: 2026-09-25