CJK Typography Testing: Chinese, Japanese, and Korean Placeholder Text Best Practices

Chinese, Japanese, and Korean (CJK) languages represent over 1.5 billion speakers and some of the world’s most lucrative digital markets. Yet CJK typography remains one of the most challenging aspects of international web design. A layout that looks perfect with Latin text or even Arabic can completely collapse when you introduce Han characters, Hiragana, or Hangul.

The reality? You cannot properly test CJK layouts with Classic Lorem Ipsum or English placeholder text. The character width, vertical rhythm, line breaking, and font requirements are fundamentally different. This comprehensive guide will show you how to test CJK typography correctly and avoid the costly mistakes that plague Western-designed sites entering Asian markets.

Understanding CJK: Three Languages, Distinct Challenges

While Chinese, Japanese, and Korean are often grouped together as “CJK,” each has unique characteristics that impact web design differently.

Chinese (中文)

Chinese placeholder text - 1.3 billion speakers

Script characteristics:

• Uses Han characters (Hanzi: 汉字)
• No spaces between words
• Simplified Chinese (mainland China, Singapore) vs. Traditional Chinese (Taiwan, Hong Kong)
• Each character typically represents a syllable or morpheme
• Extremely dense information per character

Key design challenges:

• Character-based line breaking (not word-based)
• High information density requires careful spacing
• Font files are massive (20,000+ characters vs. ~256 for Latin)
• Small text becomes illegible quickly
• Vertical text orientation still used in traditional contexts

Japanese (日本語)

Japanese placeholder text - 125 million speakers

Script characteristics:

• Three writing systems mixed together:
  • Kanji (漢字): Han characters borrowed from Chinese
  • Hiragana (ひらがな): Phonetic script for Japanese words
  • Katakana (カタカナ): Phonetic script for foreign words
• Spaces rarely used between words
• Mix of character widths (full-width vs. half-width)
• Vertical text (tategaki) still common, especially for print-inspired designs

Key design challenges:

• Three scripts with different visual weights in one sentence
• Complex line-breaking rules (cannot break between certain character pairs)
• Vertical text support needed for some designs
• Font must support all three scripts seamlessly
• Furigana (ruby text) for pronunciation guides

Korean (한국어)

Korean placeholder text - 81 million speakers

Script characteristics:

• Hangul alphabet (한글): Scientific syllabic system
• Characters formed by combining letters into syllable blocks
• Spaces used between words (unlike Chinese/Japanese)
• Occasionally mixed with Hanja (Han characters) in formal contexts
• Uniform character width

Key design challenges:

• Syllable blocks can look cramped at small sizes
• Combining jamos (letter components) requires proper font support
• Word spacing more generous than English
• Vertical stacking of vowels/consonants within characters
• South Korean vs. North Korean orthography differences

Why Latin-Script Testing Fails for CJK

Testing CJK layouts with English or Classic Lorem Ipsum will miss critical issues:

1. Character Width and Density

Latin characters are narrow and variable width. CJK characters are:

• Square and uniform: Each takes up same visual space (1em × 1em)
• Much denser: One Chinese character 工 conveys same info as “work” (4 Latin chars)
• No lowercase: All characters have same visual height

Compare these side-by-side:

• English: “International Business Corporation”
• Chinese: 国际商业公司 (same meaning, 6 characters vs. 32)

Your layout needs to work with both. Test with Chinese placeholder text to see how dense text affects your design.

2. Line Breaking Behavior

English: Breaks at word boundaries (spaces)
Chinese/Japanese: Can break between any two characters (with exceptions)
Korean: Breaks at word boundaries (like English) but words are longer on average

This affects:

• Column widths and text justification
• Hyphenation (not used in CJK)
• Orphans and widows
• Responsive breakpoints

Without authentic Japanese placeholder text, you won’t discover that your carefully designed card layout breaks when Japanese text doesn’t flow the way English does.

3. Vertical Text Support

CJK languages traditionally used vertical text (top-to-bottom, right-to-left). While horizontal text dominates modern web design, vertical text is still used for:

• Traditional designs (restaurants, cultural sites)
• Manga and comic sites
• Artistic/editorial layouts
• Book-style reading experiences

CSS supports vertical text with writing-mode:

.vertical-text {
  writing-mode: vertical-rl; /* Right-to-left columns */
  /* or vertical-lr for left-to-right columns */
}

Test vertical layouts with Chinese placeholder text or Japanese placeholder text to ensure proper character rotation and spacing.

4. Font File Size

A complete Latin font: ~50-200 KB
A complete CJK font: 5-20 MB (100x larger!)

Why? A usable CJK font needs:

• 20,000+ characters (vs. ~256 for Latin)
• Multiple weights and styles
• Proper hinting and rendering instructions for each character

This impacts:

• Page load performance
• Font loading strategies
• Subset optimization techniques
• Fallback font selection

You can’t test font loading strategies without actually loading CJK fonts with authentic placeholder text.

Setting Up Your CJK Testing Environment

1. HTML Language Declaration

Proper language attributes are critical for CJK:

<!-- Simplified Chinese -->
<html lang="zh-CN">
  <!-- Traditional Chinese (Taiwan) -->
  <html lang="zh-TW">
    <!-- Traditional Chinese (Hong Kong) -->
    <html lang="zh-HK">
      <!-- Japanese -->
      <html lang="ja">
        <!-- Korean -->
        <html lang="ko"></html>
      </html>
    </html>
  </html>
</html>

These attributes affect:

• Default font selection
• Text rendering optimizations
• Search engine indexing
• Screen reader pronunciation
• Browser translation features

2. Character Encoding

Always use UTF-8:

<meta charset="UTF-8" />

While this seems obvious, UTF-8 is essential for proper CJK character rendering. Never use legacy encodings like GB2312, Big5, Shift-JIS, or EUC-KR.

3. CSS Font Stack for CJK

Building a proper CJK font stack is complex:

/* Chinese (Simplified) */
body:lang(zh-CN) {
  font-family:
    "PingFang SC",
    /* macOS/iOS */ "Noto Sans SC",
    /* Android/Web */ "Microsoft YaHei",
    /* Windows */ "Source Han Sans SC",
    /* Adobe */ sans-serif;
}

/* Chinese (Traditional) */
body:lang(zh-TW),
body:lang(zh-HK) {
  font-family:
    "PingFang TC", "Noto Sans TC", "Microsoft JhengHei", "Source Han Sans TC",
    sans-serif;
}

/* Japanese */
body:lang(ja) {
  font-family:
    "Hiragino Sans",
    /* macOS */ "Hiragino Kaku Gothic ProN",
    /* older macOS */ "Noto Sans JP",
    /* Android/Web */ "Yu Gothic",
    /* Windows */ "Meiryo",
    /* older Windows */ "Source Han Sans JP",
    /* Adobe */ sans-serif;
}

/* Korean */
body:lang(ko) {
  font-family:
    "Apple SD Gothic Neo",
    /* macOS/iOS */ "Noto Sans KR",
    /* Android/Web */ "Malgun Gothic",
    /* Windows */ "Source Han Sans KR",
    /* Adobe */ sans-serif;
}

Test these stacks on actual devices—don’t rely on desktop browser simulation.

Testing Chinese Layouts

Simplified vs. Traditional Chinese

Always test both if targeting:

• Mainland China + Singapore: Simplified (Chinese placeholder text)
• Taiwan + Hong Kong + Macau: Traditional Chinese

The character differences affect layout:

• Traditional characters are more complex (more strokes)
• Same word can have different lengths:
  • Simplified: 计算机 (3 chars)
  • Traditional: 計算機 (3 chars but visually denser)

Chinese Typography Best Practices

Line height: Chinese needs more vertical space than English

:lang(zh-CN),
:lang(zh-TW) {
  line-height: 1.7; /* vs. 1.5 for English */
  letter-spacing: 0.05em; /* Add slight spacing for readability */
}

Font size: Chinese characters need larger base size

body {
  font-size: 16px; /* English baseline */
}

:lang(zh-CN),
:lang(zh-TW) {
  font-size: 18px; /* Increase for Chinese */
}

Test these settings with authentic Chinese placeholder text to ensure readability.

Paragraph Formatting

Chinese text traditionally has different paragraph conventions:

/* Western style: first line indent */
p {
  text-indent: 2em;
  margin-bottom: 0;
}

/* Alternative: spacing between paragraphs */
p {
  text-indent: 0;
  margin-bottom: 1em;
}

Many modern Chinese sites use the spacing approach, but traditional printing uses indentation. Test both with Chinese placeholder text.

Punctuation and Quotation Marks

Chinese uses different punctuation:

• Period: 。 (not .)
• Comma: ，(not ,)
• Quotation marks: 「」『』(not "" or ”)
• Ellipsis: …… (double, not single …)

These affect spacing and line-breaking:

/* Ensure punctuation doesn't break to new line */
:lang(zh-CN),
:lang(zh-TW) {
  line-break: strict;
  word-break: break-all;
}

E-commerce with Chinese

If you’re building e-commerce for Chinese markets, test product pages with Chinese placeholder text:

Product titles: Much shorter in Chinese
Descriptions: More dense, need careful line-height
Reviews: User-generated content often mixes Chinese with English brand names
Prices: Use proper Chinese number formatting (¥1,234.56)

For fashion e-commerce, consider how Fashion Ipsum would translate—fashion terms are often kept in English in Chinese markets.

Business Sites for Chinese Markets

Corporate sites need special consideration. Test with Corporate Ipsum alongside Chinese placeholder text:

Executive names: Often shown in both Chinese and English
Company names: Frequently in English with Chinese description
Technical terms: Tech companies often keep English terms

Example mixed content:

公司首席执行官 John Smith 宣布新的 AI 战略
(Company CEO John Smith announces new AI strategy)

Testing Japanese Layouts

Japanese is the most complex CJK language for typography due to three writing systems in one text.

The Three-Script Challenge

A typical Japanese sentence mixes all three:

私はコンピューターで仕事をします。
I    computer     work do
(Hiragana)(Katakana)(Kanji)

Test your layout with authentic Japanese placeholder text to see how these scripts interact.

Character Mixing and Visual Weight

Each script has different visual weight:

• Kanji: Dense, square, heavy
• Hiragana: Curved, lighter, flowing
• Katakana: Angular, lighter than Kanji, heavier than Hiragana

This creates natural visual rhythm but requires fonts that balance all three:

:lang(ja) {
  font-family: "Hiragino Sans", "Yu Gothic", sans-serif;
  line-height: 1.7;
  letter-spacing: 0.03em;
}

Line Breaking Rules

Japanese has strict line-breaking rules (kinsoku shori 禁則処理):

Cannot start line with:

• Closing punctuation: 」』）】
• Small kana: ゃゅょっ
• Iteration marks: 々ゝゞ
• Certain particles: をは

Cannot end line with:

• Opening punctuation: 「『（【

CSS handles this with:

:lang(ja) {
  line-break: strict; /* Enforce kinsoku rules */
  word-break: normal; /* Don't break within words */
  overflow-wrap: break-word; /* Break long words if necessary */
}

Test these rules with Japanese placeholder text—they affect how text flows in narrow containers.

Vertical Text (Tategaki)

Japanese vertical text is still common for:

• Traditional restaurant sites
• Manga/anime platforms
• Cultural/artistic sites
• Book-reading interfaces

.vertical-japanese {
  writing-mode: vertical-rl;
  text-orientation: upright;
}

/* Rotate half-width characters */
.vertical-japanese {
  text-combine-upright: all; /* Combine small text groups */
}

Critical issues to test:

• Punctuation rotation
• Number formatting (horizontal in vertical text)
• Latin text rotation
• Mixed script handling

Use Japanese placeholder text in both horizontal and vertical layouts to ensure proper rendering.

Ruby Text (Furigana)

Ruby text shows pronunciation above/beside Kanji:

<ruby> 漢字<rp>(</rp><rt>かんじ</rt><rp>)</rp> </ruby>

This affects:

• Line height (needs more space)
• Responsive breakpoints
• Font size relationships
• Mobile readability

Test ruby text with Japanese placeholder text to ensure adequate spacing.

Japanese Typography for Tech

If building tech products for Japanese markets, test with Technology Ipsum and Japanese placeholder text:

Code examples: Often mix Japanese comments with English code
UI labels: Mix of Japanese and English terms
Error messages: Usually in Japanese with English error codes
Documentation: Heavy use of katakana for technical terms

For AI/ML products, also test with AI Ipsum—many AI terms stay in English even in Japanese interfaces.

Testing Korean Layouts

Korean is technically the “easiest” CJK language for web typography due to its alphabetic nature and word spacing.

Hangul Typography Basics

Hangul characters are syllable blocks formed by combining:

• Choseong (initial consonant): ㄱ ㄴ ㄷ etc.
• Jungseong (vowel): ㅏ ㅓ ㅗ etc.
• Jongseong (final consonant, optional): ㄱ ㅁ ㅇ etc.

Example: 한 = ㅎ(h) + ㅏ(a) + ㄴ(n) = “han”

Fonts must properly compose these elements:

:lang(ko) {
  font-family:
    "Apple SD Gothic Neo", "Noto Sans KR", "Malgun Gothic", sans-serif;
  line-height: 1.6;
  word-spacing: 0.1em; /* Korean uses more word spacing */
}

Test composition with Korean placeholder text.

Word Spacing in Korean

Unlike Chinese/Japanese, Korean uses spaces between words. This creates different design considerations:

:lang(ko) {
  word-break: keep-all; /* Keep Korean words together */
  word-spacing: 0.1em; /* Increase spacing between words */
}

Korean words can be quite long (like German), so test narrow columns with Korean placeholder text.

Korean Typography Best Practices

Line height: Slightly less than Chinese/Japanese but more than English

:lang(ko) {
  line-height: 1.6;
  letter-spacing: 0; /* Korean doesn't need extra letter spacing */
}

Font weight: Korean characters can look heavy, so use lighter weights:

:lang(ko) {
  font-weight: 400; /* vs 500 for English */
}

:lang(ko) strong {
  font-weight: 700; /* vs 800 for English */
}

Hanja (Chinese Characters in Korean)

Formal Korean text sometimes includes Hanja (한자):

大韓民國 (대한민국) - Republic of Korea

Your font stack must support both Hangul and Hanja. Test with Korean placeholder text that includes Hanja.

Korean E-commerce Considerations

K-beauty, K-fashion, and Korean e-commerce are booming. Test product sites with Korean placeholder text:

Product names: Often mix Korean with English brand names
Descriptions: Long paragraphs with generous word spacing
Reviews: Highly detailed, need good typography for readability
Categories: Mix of Korean and English terms

For fashion sites, see how Fashion Ipsum concepts translate to Korean markets.

Cross-CJK Testing Strategy

Many products need to support all three CJK languages. Here’s a comprehensive testing approach:

Phase 1: Character Rendering

Test that your fonts properly render:

• Chinese Simplified characters
• Chinese Traditional characters
• Japanese Kanji + Hiragana + Katakana
• Korean Hangul blocks
• Mixed CJK (Chinese name in Japanese text)

Phase 2: Line Breaking

Test line-breaking behavior in:

• Narrow columns (mobile)
• Flexible containers (responsive)
• Fixed-width containers (cards)
• Mixed LTR/CJK text

Use Chinese, Japanese, and Korean placeholder text in the same layout to see differences.

Phase 3: Typography Scale

Test font sizes from small to large:

• Body text (16-18px)
• Small text (12-14px) - especially important for CJK
• Large headings (32-48px)
• Extra-large display text (64px+)

CJK characters become illegible faster than Latin text at small sizes.

Phase 4: Vertical Text (Optional)

If supporting vertical text:

• Character orientation
• Punctuation rotation
• Number handling
• Mixed script rotation

Phase 5: Performance

Test font loading with:

• Subset optimization
• Font-display strategies
• Fallback behavior
• FOIT (Flash of Invisible Text) prevention

Font Optimization for CJK

CJK font files are huge. Optimization is critical:

1. Font Subsetting

Include only characters you need:

# Example using fonttools to subset Chinese font
from fontTools.subset import main as subset

subset([
  'NotoSansSC-Regular.otf',
  '--text-file=characters-needed.txt',  # Your actual characters
  '--output-file=NotoSansSC-subset.woff2',
  '--flavor=woff2'
])

A full Chinese font: 15 MB
Subset to common 3,500 characters: 1.5 MB
Subset to your actual content: 200-500 KB

2. Google Fonts with Language Parameter

Google Fonts optimizes CJK automatically:

<!-- Full font: very large -->
<link
  href="https://fonts.googleapis.com/css2?family=Noto+Sans+SC"
  rel="stylesheet"
/>

<!-- Subset by language: much smaller -->
<link
  href="https://fonts.googleapis.com/css2?family=Noto+Sans+SC&subset=chinese-simplified"
  rel="stylesheet"
/>

3. Font-Display Strategy

Prevent invisible text while loading:

@font-face {
  font-family: "Noto Sans SC";
  src: url("/fonts/NotoSansSC.woff2") format("woff2");
  font-display: swap; /* Show fallback immediately, swap when loaded */
  unicode-range: U+4E00-9FFF; /* CJK Unified Ideographs */
}

4. Preload Critical Fonts

<link
  rel="preload"
  href="/fonts/NotoSansSC-subset.woff2/"
  as="font"
  type="font/woff2"
  crossorigin
/>

Test font loading performance with authentic Chinese placeholder text, Japanese placeholder text, and Korean placeholder text.

Responsive CJK Design

CJK text behaves differently at various screen sizes:

Mobile Considerations

/* Increase base size on mobile for CJK */
:lang(zh-CN),
:lang(zh-TW),
:lang(ja),
:lang(ko) {
  font-size: 16px;
}

@media (max-width: 768px) {
  :lang(zh-CN),
  :lang(zh-TW),
  :lang(ja),
  :lang(ko) {
    font-size: 17px; /* Larger on mobile */
    line-height: 1.8; /* More breathing room */
  }
}

Tablet and Desktop

@media (min-width: 768px) {
  :lang(zh-CN),
  :lang(zh-TW),
  :lang(ja),
  :lang(ko) {
    font-size: 18px;
    line-height: 1.7;
  }
}

@media (min-width: 1024px) {
  :lang(zh-CN),
  :lang(zh-TW),
  :lang(ja),
  :lang(ko) {
    font-size: 19px;
    max-width: 40em; /* Comfortable reading length */
  }
}

Column Width

CJK text needs different optimal line lengths:

English: 60-75 characters optimal
CJK: 30-40 characters optimal (because each is more information-dense)

/* English */
.content {
  max-width: 65ch;
}

/* CJK */
:lang(zh-CN) .content,
:lang(zh-TW) .content,
:lang(ja) .content {
  max-width: 35em; /* Comfortable width for CJK */
}

:lang(ko) .content {
  max-width: 40em; /* Korean words are longer */
}

Common CJK Typography Mistakes

Mistake 1: Using English Font Sizes

/* WRONG - too small for CJK */
body {
  font-size: 14px;
}

/* RIGHT - adequate for CJK */
body {
  font-size: 16px;
}

:lang(zh-CN),
:lang(ja),
:lang(ko) {
  font-size: 18px;
}

Mistake 2: Insufficient Line Height

/* WRONG - too cramped for CJK */
p {
  line-height: 1.4;
}

/* RIGHT - breathable for CJK */
p {
  line-height: 1.5;
}

:lang(zh-CN),
:lang(ja),
:lang(ko) {
  line-height: 1.7;
}

Mistake 3: Not Testing Character Limits

A 20-character English heading might be 10 characters in Chinese. Test with real Chinese placeholder text:

/* Ensure headings work at all lengths */
h1 {
  min-height: 2.5em; /* Prevent layout shift */
  overflow-wrap: break-word;
}

Mistake 4: Forgetting About Font Loading

/* WRONG - invisible text while loading */
body {
  font-family: "Noto Sans SC", sans-serif;
}

/* RIGHT - show fallback, swap when ready */
@font-face {
  font-family: "Noto Sans SC";
  src: url("/fonts/NotoSansSC.woff2") format("woff2");
  font-display: swap;
}

Mistake 5: Not Considering Vertical Text

If you’re designing for Japanese markets, at least consider vertical text for:

• Hero sections
• Artistic headers
• Traditional restaurant sites
• Manga/reading apps

Test vertical layouts with Japanese placeholder text.

Framework-Specific CJK Support

React and Next.js

// Use next-intl for CJK support
import { useLocale } from "next-intl";

function Component() {
  const locale = useLocale();
  const isCJK = ["zh-CN", "zh-TW", "ja", "ko"].includes(locale);

  return (
    <div lang={locale} className={isCJK ? "cjk-typography" : ""}>
      {/* Content with appropriate placeholder text */}
    </div>
  );
}

Vue.js

<template>
  <div :lang="$i18n.locale" :class="cjkClass">
    <!-- Test with Chinese, Japanese, or Korean placeholder text -->
  </div>
</template>

<script>
export default {
  computed: {
    cjkClass() {
      return ["zh-CN", "zh-TW", "ja", "ko"].includes(this.$i18n.locale)
        ? "cjk-typography"
        : "";
    },
  },
};
</script>

Tailwind CSS

Create CJK-specific utilities:

// tailwind.config.js
module.exports = {
  theme: {
    extend: {
      fontSize: {
        "cjk-base": "18px",
        "cjk-lg": "20px",
        "cjk-xl": "24px",
      },
      lineHeight: {
        cjk: "1.7",
        "cjk-relaxed": "1.8",
      },
    },
  },
};

<div class="text-base lg:text-cjk-base leading-cjk">
  <!-- Chinese placeholder text -->
</div>

Industry-Specific CJK Considerations

Technology & SaaS

Tech products for CJK markets need special care. Test with Technology Ipsum and Chinese/Japanese/Korean placeholder text:

UI labels: Often keep English terms (Login, API, Dashboard)
Documentation: Mix of CJK and code blocks (always LTR)
Error messages: Technical details in English, explanation in CJK
Navigation: Shorter in CJK, needs flexible width

For AI products, test with AI Ipsum—many AI/ML terms stay in English even in CJK interfaces.

E-commerce

Product pages need careful testing:

• Titles: Much shorter in Chinese
• Descriptions: Denser, need good line-height
• Reviews: CJK reviews tend to be longer and more detailed
• Categories: Often bilingual

Test fashion sites with Fashion Ipsum concepts translated to CJK markets.

Corporate Sites

Business sites often mix CJK and English. Test with Corporate Ipsum:

Executive bios: Names in both languages
Press releases: Formal language, longer in CJK
Financial data: Numbers in English format, labels in CJK
Legal: Very formal CJK, Legal Ipsum concepts apply

Gaming and Entertainment

Manga, anime, and gaming sites need:

• Vertical text support (Japanese)
• Ruby text for character names
• Mixed fonts for impact
• Stylized typography

Food and Restaurant

Restaurant sites often use vertical text. Test with Food Ipsum and:

• Chinese placeholder text for Chinese restaurants
• Japanese placeholder text for Japanese restaurants
• Korean placeholder text for Korean restaurants

Traditional designs may need vertical text support.

Testing Checklist for CJK

Use this comprehensive checklist:

✅ Basic Setup

• UTF-8 encoding set
• Correct lang attribute (zh-CN, zh-TW, ja, ko)
• Appropriate font stack with CJK fonts
• Font files optimized/subset
• Font-display strategy implemented

✅ Typography

• Base font size adequate (18px+ for CJK)
• Line height generous (1.7-1.8)
• Letter spacing appropriate
• Word spacing (Korean)
• Small text still readable

✅ Line Breaking

• word-break settings correct
• line-break settings correct
• Narrow containers tested
• Long words/phrases handled

✅ Mixed Content

• CJK + English mixed properly
• Numbers render correctly
• Punctuation displays properly
• Code blocks stay LTR

✅ Responsive

• Mobile font sizes adequate
• Tablet layouts work
• Desktop max-width appropriate
• All breakpoints tested with CJK text

✅ Performance

• Font files optimized
• Preloading critical fonts
• Fallback fonts appropriate
• No FOIT (Flash of Invisible Text)

✅ Language-Specific

• Chinese Simplified vs Traditional
• Japanese three-script support
• Korean Hangul composition
• Hanja support if needed

✅ Advanced (if applicable)

• Vertical text support
• Ruby text (furigana)
• Character spacing in headings
• Print stylesheets

Resources for CJK Testing

Essential Fonts

Chinese:

• Noto Sans SC/TC (Google)
• Source Han Sans SC/TC (Adobe)
• PingFang SC/TC (System, Apple)

Japanese:

• Noto Sans JP (Google)
• Source Han Sans JP (Adobe)
• Hiragino Sans (System, Apple)

Korean:

• Noto Sans KR (Google)
• Source Han Sans KR (Adobe)
• Apple SD Gothic Neo (System, Apple)

Testing Tools

• PlaceholderText.org: Chinese, Japanese, Korean generators
• Google Fonts: CJK font testing
• BrowserStack: Test on actual devices in Asian locales
• Font Squirrel Webfont Generator: For font subsetting

Further Reading

• W3C Internationalization: Chinese Layout Requirements
• W3C Internationalization: Japanese Layout Requirements
• Unicode Technical Report #50: Unicode Vertical Text Layout
• CSS Writing Modes Level 4 Specification

Conclusion: CJK Typography is Non-Negotiable

With over 1.5 billion speakers and three of the world’s largest tech markets (China, Japan, South Korea), proper CJK typography isn’t optional—it’s essential for any global product.

The key principles:

1. Never test with Latin text - Use authentic Chinese placeholder text, Japanese placeholder text, and Korean placeholder text

2. Increase font sizes - 18px+ base size for CJK, larger than English

3. Generous spacing - 1.7-1.8 line-height, adequate letter/word spacing

4. Optimize fonts - Subset to needed characters, use font-display: swap

5. Test line breaking - Each CJK language has different rules

6. Consider vertical text - Especially for Japanese traditional designs

7. Performance matters - CJK fonts are huge, optimize carefully

Ready to test your CJK layouts? Start with our Chinese, Japanese, or Korean placeholder text generators, and use this guide to ensure your designs work perfectly for East Asian audiences.

Remember: A layout that works beautifully with English can completely fail with CJK characters. Test early, test often, and test with authentic language placeholder text. Your Asian users will thank you.

Last updated: January 2026.