Novel Ruby Density Analyzer｜Visualize & Balance Your Japanese Prose

This tool analyzes Japanese novel text to calculate and visualize two key metrics: Kanji Ratio and Ruby (furigana) Density. It's designed for authors, editors, and translators to help them achieve a more balanced and readable prose by providing objective data on text complexity and style.

💡 Tool Overview

• Real-time Analysis: Get instant feedback on your text as you type or paste. The report updates automatically with every change.
• Kanji Ratio Visualization: See the percentage of Kanji in your text, a key indicator of visual density or "textual darkness." The tool evaluates if the ratio is in the ideal range (20-30%), too heavy (>30%), or too light.
• Ruby Density Check: Measures the frequency of ruby (furigana) characters. This helps you avoid overuse, which can disrupt the reading flow. A density under 5% is generally recommended.
• Downloadable Report: Export the complete analysis report as a high-quality PNG image, perfect for sharing with editors, archiving your progress, or including in writing portfolios.
• Privacy-Focused: All analysis is performed directly in your browser. Your text is never sent to or stored on a server.

🧐 Frequently Asked Questions (FAQ)

Q. What does "Kanji Ratio" signify?

A. Kanji Ratio is the percentage of Kanji characters relative to the total text. In Japanese publishing, this is often conceptually linked to "textual darkness" (紙面の黒さ, shimen no kurosa). A high ratio (>30%) can make the page look visually dense and feel more formal or difficult to readers, while a very low ratio might seem too simplistic. The ideal balance often lies between 20-30%.

Q. Why is "Ruby Density" important?

A. Ruby (or furigana) are phonetic guides placed over Kanji. They are essential for clarifying unusual readings, introducing special terms, or for stylistic effect. However, excessive use can clutter the page and slow down the reading pace for fluent readers. This tool helps you maintain a balance, ensuring ruby is used effectively without overwhelming the reader.

📚 Pro-Tip: The Art of Textual Balance

In the world of Japanese typography and editing, the visual impression of a page is paramount. Editors often speak of "Kuromen" (黒面, "black page") and "Shiromen" (白面, "white page"). A page dense with complex Kanji looks "blacker" and can feel more academic or heavy. Conversely, a page with a high proportion of Hiragana appears "whiter" and is generally considered easier and quicker to read, though it can risk appearing juvenile if overdone.

Professional writers and editors constantly strive for the right balance to match their content and target audience. This tool demystifies that process by quantifying an editor's intuition into actionable data. It allows you to objectively assess whether your prose hits the desired tone, helping you refine your writing to be as engaging and readable as possible.