📊 Readability Checker

Analyzes Japanese text readability from multiple perspectives and displays an overall score with specific improvement suggestions.

0 character
0
Overall Score / 100

💡 Improvement Suggestions

Text Highlighting

Sentences That Are Too Long (Over 80 Characters) Passive Voice

Usage and Application Examples

  • Simply input text and click "Analyze" to begin analysis
  • Perfect for checking text before publishing blog posts or reports
  • 25-35% kanji usage is the guideline for readable text
  • Sentences of 80+ characters are highlighted in red
  • Passive voice is highlighted in orange, prompting rewriting in active voice
  • More accurate analysis results with text of 200+ characters

What is Text Readability Analyzer?

A text readability analyzer automatically evaluates how easily readers can comprehend Japanese text by measuring factors like average sentence length, kanji density, and vocabulary complexity. This free tool provides an overall readability score and detailed metrics, helping writers optimize their content for target audiences. Whether preparing academic papers, blog posts, or professional documentation, a readability checker ensures your writing communicates effectively and remains accessible to your intended readers.

How to Use

Paste your Japanese text into the analyzer's input field and click analyze. The tool instantly generates a readability score ranging from easy to difficult, displays average sentence length in characters, calculates kanji percentage, and provides metrics on vocabulary diversity. Review the detailed breakdown to identify problematic areas—overly long sentences reduce readability, while excessive kanji makes text difficult for non-specialized readers. Make targeted edits based on the report: shorten sentences, replace difficult kanji with simpler alternatives, or add furigana annotations. Re-analyze after editing to verify improvements.

Use Cases

Educational content creators optimize materials for specific grade levels and student comprehension levels. Technical writers simplify complex documentation to ensure broader audience understanding. News organizations analyze articles to ensure general audiences can follow stories. Medical and legal professionals test whether important documents are accessible to non-specialists. Content marketing specialists optimize posts for readability to improve engagement metrics. Publishing companies evaluate manuscript readability before printing to match target reader demographics. Teachers assess student writing assignments for clarity and appropriate vocabulary complexity.

Tips & Insights

Japanese readability is complex because it combines hiragana, katakana, and kanji—even identical meaning can vary dramatically in difficulty depending on character choices. News outlets typically target readability scores equivalent to 8–12th grade reading level. Academic papers intentionally use higher kanji density and complex sentences, but even specialized audiences benefit from organized structure. Flesch-Kincaid formulas don't perfectly translate to Japanese; they're approximate guides. Breaking content into shorter paragraphs and using section headings significantly improves perceived readability regardless of sentence metrics.

Frequently Asked Questions

How is the overall score calculated?
We comprehensively evaluate multiple indicators including average sentence length, kanji usage rate, hiragana rate, passive voice percentage, and number of overly long sentences, and calculate them as a score from 0 to 100. Higher scores indicate more readable text.
What is an appropriate kanji usage rate?
Generally, readable text has a kanji usage rate of 25-35%. Newspaper articles are around 30%, and web articles are typically 25-30%. Too much kanji gives a stiff impression, while too little gives a childish impression.
What is an appropriate sentence length?
The ideal character count per sentence in readable text is 40-60 characters. Sentences exceeding 80 characters tend to be harder to read, and breaking them with punctuation is recommended.
Is text with more passive voice harder to read?
Too much passive voice (such as ~される, ~られる) makes the subject ambiguous and the text harder to understand. Rewriting in active voice makes the text clearer and more readable.
Is data sent to the server?
No. All analysis is performed in your browser, and your text is never sent to our servers. Please use with confidence.
What metrics besides sentence length does the tool analyze?

Beyond sentence length, the tool measures kanji usage rate, passive voice proportion, and word distribution to assess overall readability comprehensively. It also analyzes paragraph structure to identify overly complex sections. These combined metrics reveal whether text is too technical, too passive, or structurally difficult.

Can this tool analyze English text or only Japanese?

This tool is specifically designed for Japanese text and uses metrics like kanji rate that are unique to Japanese writing. English text analysis requires different metrics like Flesch-Kincaid grade level or Gunning Fog Index. For English readability, use dedicated English tools; this one is optimized for Japanese writing standards.

What is considered 'difficult' kanji in the analysis?

The tool typically classifies kanji as difficult if they are outside the Jōyō Kanji list (2,136 common characters taught in schools) or require uncommon readings. Difficult kanji increases reader cognitive load, especially for younger or less experienced readers. The analysis recommends limiting difficult kanji or adding furigana (ruby text) for improved readability.

Can I export or save my readability analysis results?

The tool displays real-time analysis on screen; check for copy, download, or export buttons in the interface for saving results. Most browser tools allow manual copying or screenshots of the analysis data. Persistent storage depends on implementation—check if the tool supports exporting as text or PDF formats.

How accurate is the readability score and what factors influence it most?

The overall score combines multiple factors, with sentence length and passive voice typically having the strongest influence on ratings. The score provides directional guidance rather than absolute measurement—improving the weakest metrics usually improves the overall score significantly. Treat it as a revision guide rather than targeting a specific numerical score.

Is there a maximum text length I can analyze at once?

Browser-based tools have practical limits based on processing power; very large documents (50,000+ characters) may process slowly or timeout. For lengthy content, analyze sections separately to identify which parts need readability improvement. If you hit performance issues, paste text in smaller chunks.