🛠️ FreeTool.jp JP
FAQ Privacy Policy

Duplicate Content Checker

Compare two texts and calculate similarity percentage

SEO

重複コンテンツ比較

2つのテキストを比較して類似度をパーセンテージで判定します

言い換えテキストをより正確に検出します

すべての処理はブラウザ内で完結します。

About Duplicate Content Checker

The Duplicate Content Checker analyzes text similarity using N-gram analysis with two comparison modes: character-level and word-level. Japanese text uses 3-grams and English uses 5-grams by default, optimized for each language. Calculates similarity precisely using the Jaccard coefficient.

Word-level comparison employs research-backed methodology to detect paraphrased and reworded content more accurately than character-level analysis alone. Results are color-coded: green for low similarity (0-30%), yellow for medium (30-60%), red for high (60-100%). Helps prevent Google penalties from duplicate content in your SEO strategy.

Ideal for verifying article rewrites, checking outsourced content originality, detecting internal document plagiarism, and pre-checking academic papers. All processing runs entirely in your browser—text data is never sent to any server for maximum privacy.

How to use Duplicate Content Checker

  1. Enter or paste the source text in the left (top) text area.
  2. Enter or paste the comparison text in the right (bottom) text area.
  3. Click the 'Compare' button to see the similarity analysis results.
  4. Check the similarity percentage and color coding to assess duplication risk, and revise text as needed.

Benefits of Duplicate Content Checker

  • Two comparison modes (character-level and word-level) detect everything from exact duplicates to paraphrased content.
  • N-gram analysis and Jaccard coefficient deliver accurate, research-backed similarity detection.
  • Automatic language detection optimizes N-gram size for Japanese and English. Color-coded results for instant risk assessment.
  • Detailed statistics (matching N-grams, total N-grams, word count, character count) enable deep analysis.
  • Browser-based processing ensures your confidential text data never leaves your device or reaches any server.

他のカテゴリ

Image Tools PDF Tools Text Tools Audio Tools Video Tools Calculators Business Documents Design Tools

SEO & Web の人気ツール TOP 10

🌐 Alt Check
🌐 robots.txt Gen
🌐 UTM Builder
🌐 Heading Check
🌐 Canonical Gen
🌐 FAQ Schema Gen
🌐 robots.txt Test
🌐 SEO Title Check
🌐 Breadcrumb Gen
🌐 GA4 Event Gen

SEO & Web のすべてのツール (13件)