Japanese Text

Special handling for Japanese (CJK) text formatting

The problem with general formatters

Most markdown formatters apply Western typographic rules that do not work well with Japanese (CJK) text. Common issues include:

Line reflow — Formatters reflow paragraphs to fit a line width. Since Japanese does not use spaces between words, the formatter cannot determine where to break lines, resulting in inappropriate joins or splits.
Unwanted backslashes — Some formatters insert \ at line ends to preserve hard line breaks, cluttering Japanese text with unnecessary escape characters.
Space insertion — Formatters may add spaces around emphasis markers (**bold**), punctuation (。、), or between Japanese and ASCII characters where none should exist.
HTML entity encoding — Characters like を can get encoded to を, making the source unreadable.

These issues make general-purpose formatters difficult to use in projects that contain Japanese markdown content.

How mdx-formatter handles Japanese text

Japanese text is preserved as-is by the formatter. The formatter does not insert or remove spaces around Japanese punctuation. This works through the formatter’s text-preservation approach — the hybrid line-based formatter preserves original text for content it does not specifically transform.

Japanese punctuation spacing is preserved
No extra spaces are inserted around Japanese characters
Bold/emphasis markers work correctly with Japanese text
URLs and parenthetical expressions in Japanese text are preserved
Line breaks within Japanese paragraphs are not altered

Examples

Japanese headings and content

Before:

# 日本語の見出し
内容です。

After:

# 日本語の見出し

内容です。

Bold text with Japanese

Japanese bold text is preserved without unwanted space changes:

Before:

この値を **×2** します

After (unchanged):

この値を **×2** します

Image alt text with Japanese and colons

Before:

![図:VCAによるオーディオシグナルの減衰処理](/images/p/vca-exp-2)

After (unchanged — colons and Japanese in alt text preserved):

![図:VCAによるオーディオシグナルの減衰処理](/images/p/vca-exp-2)

URLs in parenthetical expressions

Before:

詳細は (https://example.com) をご覧ください

After (unchanged — parentheses around URL preserved):

詳細は (https://example.com) をご覧ください

Multi-line Japanese paragraphs

Line breaks within Japanese paragraphs are preserved as-is:

Before:

こんにちは、Takazudo Modularです。
Takazudo Modular Highlightsなどというメルマガの名前にしてみました。
そんな年中送るかは分かりませんが……。

After (unchanged):

こんにちは、Takazudo Modularです。
Takazudo Modular Highlightsなどというメルマガの名前にしてみました。
そんな年中送るかは分かりませんが……。