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Overview

Kanji Density Analyzer

Measure the ratio of kanji, hiragana, katakana, and romaji in a Japanese passage. Use the kanji percentage to gauge reading difficulty for textbooks, blogs, JLPT prep, and editorial content.

What isHow to useExampleCommon use casesFrequently asked questions

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#kanji-density#japanese-readability#script-balance#jlpt-prep#japanese-editing

Kanji Density Analyzer

Measure the ratio of kanji, hiragana, katakana, and romaji in a Japanese passage. Use the kanji percentage to gauge reading difficulty and target audience.

Paste Japanese text above to see kanji / kana / romaji breakdown.

What you can solve

My JLPT reading passage feels too formal — how do I confirm it before students complain?

Run the passage through the analyzer. If kanji density exceeds the academic/formal band (>40%) but the target is N3 students, you have an objective signal to rewrite. Replace 漢字熟語 with kana phrases or simpler equivalents until the ratio falls into the 28–35% range and re-measure.

My Chinese-to-Japanese translation reads heavy — is it the kanji ratio?

Translators converting from Chinese sometimes leave too many compound terms in kanji because the equivalent character exists. A density above 45% in a casual context is usually the signal to break compounds into kana-mixed forms (例えば → たとえば, 即時 → すぐに). Use the analyzer to set a target band, then revise.

My Japanese blog post feels childish even though I worked hard on the writing — why?

If your kanji density is below 20% in a topic that adult readers expect to see written formally (business, tech, finance), the writing reads as for children regardless of vocabulary choice. Push kanji density into the 25–32% casual blog band by converting selected kana phrases back to kanji where natural.

How do I extract a unique kanji list from a long Japanese article?

Paste the article and copy the deduplicated kanji from the unique kanji panel. This gives you a vocabulary study set ordered by Unicode codepoint — easy to import into Anki or feed into a JLPT level checker.

Can I compare kanji density between two authors or two genres objectively?

Yes — paste representative passages (2,000+ characters each for stable averages) and compare the kanji density bands. Differences of more than 5 percentage points usually correspond to a visible style or genre difference. Below that, the variance is within normal author-to-author noise.

Typical workflow

Japanese Text Counter - Ninja Character CounterKanji Density AnalyzerJapanese Character Limit Checker

Guides for this workflow

Supporting guides that connect this tool to the broader category workflow.

Open category hub
Language guide

Japanese Writing & Content Creation Hub: Counters, Readability, and Romanization

A workflow hub for Japanese writers, teachers, and content creators — character counters, kanji density, JLPT level checking, romanization, manuscript paper, and reading-time estimation in one map.

Language guide

Check Japanese Character Limits Before Submitting Essays and Entry Sheets

A practical workflow for checking Japanese character limits before submission so a draft does not fail because it is visibly short, quietly over, or counted under the wrong rule.

Language guide

Estimate Japanese Reading Time for Scripts, Lessons, and Study Content

A workflow for estimating Japanese silent reading and read-aloud time so scripts, lessons, and study materials fit their real timing constraints.

Language guide

When to Use Genkouyoushi Counts Instead of Raw Character Count

A practical guide to when Japanese writing should be thought of in manuscript-paper sheets instead of raw characters, especially for assignments, essays, and draft planning.

What is

What is Kanji Density Analyzer?

Japanese readability is partly a kanji-density question. The same sentence rewritten with more kana feels lighter; the same sentence rewritten with more kanji feels denser and more formal. Editors, JLPT material authors, and bilingual writers regularly tune this ratio without an explicit measurement — this tool makes the ratio explicit so the tuning can be deliberate.

The analyzer counts every visible character by script: kanji (CJK Unified Ideographs across all extensions), hiragana, katakana (both standard and half-width), romaji (full-width and half-width), digits, punctuation, whitespace, and other symbols. The kanji percentage is reported against visible characters (whitespace excluded) so it stays meaningful regardless of line-break style.

How to use

How to use Kanji Density Analyzer

1. Paste any Japanese passage into the input area.

2. The counts, kanji density bar, and unique-kanji list update instantly.

3. Compare the kanji percentage against the readability band: <20% children, 20–30% casual, 30–40% news/business, 40–50% academic, 50%+ legal/technical.

4. Copy the unique kanji list for vocab study or to spot-check JLPT level coverage.

Example

Example

Sample paragraph (40 visible chars):
• Kanji 12 (30.0%) — general news/business band
• Hiragana 18 (45.0%)
• Katakana 6 (15.0%)
• Romaji 0 (0.0%)
• Punctuation 4 (10.0%)

Common use cases

Common use cases

1. JLPT material authors checking that a N3 reading passage stays under 30% kanji density.

2. Editors targeting Yahoo News / blog tone (28–34%) without overcorrecting toward textbook style.

3. Translators measuring whether a Chinese-to-Japanese translation has imported too many kanji.

4. Researchers profiling a corpus by script balance before deciding which segmentation tool to use.

Frequently asked questions

Frequently asked questions

How does whitespace affect the percentage?v
Whitespace is counted separately but excluded from the visible-character denominator. That keeps the kanji percentage stable whether the source has tight line breaks, double-spacing, or full-width 　 ideographic spaces.
Why is the kanji band labeled 'news/business' at 30–40%?v
Empirical surveys of Japanese newspapers (Asahi, Yomiuri) and corporate communication put kanji density around 30–37%. JLPT N3 reading sits near 28–32%. Light novels often sit at 25–32%. Use the band as a rough comparative reference, not an absolute prescription.
Does the unique kanji list help with JLPT vocabulary checks?v
Yes — copy the unique list and paste it into a JLPT level checker to see which level each kanji belongs to. The density tool tells you the volume; the level checker tells you the difficulty distribution.