This document points to resources for the layout and presentation of text in languages that use the Japanese script. The target audience includes developers of Web standards and technologies, such as HTML, CSS, Mobile Web, Digital Publications, and Unicode, as well as implementers of web browsers, ebook readers, and other applications that need to render Japanese text.

This document points to resources for Japanese script layout and text support on the Web and in eBooks. These requirements provide information for Web technologies such as CSS, HTML and digital publications about how to support languages written using the Japanese script. The information here is developed in conjunction with a document that summarises gaps where the Web fails to adequately support the Japanese script.

The editor's draft of this document is being developed in the GitHub repository Japanese Language Enablement (jlreq), with contributors from the W3C Internationalization Interest Group. It is published by the Internationalization Working Group. The end target for this document is a Working Group Note.

To make it easier to track comments, please raise separate issues or emails for each comment, and point to the section you are commenting on using a URL.

Some links on this page point to repositories or pages to which information will be added over time. Initially, the link may produce no results, but as issues, tests, etc. are created they will show up.

Links that have a gray color led to no content the last time this document was updated. They are still live, however, since relevant content could be added at any time. When the document is updated, links that now point to results will have their live colour restored.

Introduction

Contributors

This document was created by Richard Ishida.

See also the GitHub contributors list for the Japanese Language Enablement project, and the discussions related to the Japanese script.

About this document

This document points to resources for Japanese script layout and text support on the Web and in eBooks. These resources provide information for developers of Web technologies such as CSS, HTML and digital publications, and for application developers, about how to support languages written using the Japanese script. They include requirements, tests, GitHub discussions, type samples, and more,

The document focuses on typographic layout issues. For a deeper understanding of the Japanese script and how it works see Japanese Orthography Notes, which includes topics such as: Phonology, and Characters.

Gap analysis

This document should be used alongside a separate document, Japanese Gap Analysis, which describes gaps in language support for users of the Japanese script, and prioritises and describes the impact of those gaps on the user.

Gap reports are brought to the attention of spec and browser implementers, and are tracked via the Gap Analysis Pipeline. (Filter for Japanese script items)

Related resources

The document Language enablement index points to this document and others, and provides a central location for developers and implementers to find information related to various scripts.

The W3C also has a repository with discussion threads related to the Japanese script, including requests from developers to the user community for information about how scripts/languages work, and a notification system that tracks issues in W3C working groups related to the Japanese script. See a list of unresolved questions for Japanese experts. Each section below points to related discussions. See also the repository home page.

Japanese Script Overview

Four scripts are used, mixed together to write Japanese: kanji (han), katakana, hiragana, and latin. Essentially, Japanese writing is a mixture of an ideographic and a syllabic script. Non-latin letters typically represent a spoken syllable. The character count reflects a typical set of characters needed for everyday reading and writing: there are thousands more kanji characters that could be added for other purposes.

Text can be written horizontally or vertically. The visual forms of characters don't interact, but rotated and alternative glyph forms are needed to enable the switch between directions.

Words are not separated by spaces or any other character. There is no case distinction. The visual forms of characters don't interact.

Kanji characters are mostly derived from the Chinese Han script. They are used for word roots.

The term kana covers two syllabaries that are used with kanji characters to write Japanese.

One syllabary is hiragana, the other katakana. In both cases, the repertoire includes 5 independent vowel sounds, one nasal sound, and the rest are consonant+vowel combinations. There are a small number of additional characters with particular functions, such a katakana lengthening mark, and a few small characters for representing medial glides.

The Latin (romaji) characters and much of the punctuation corresponding to the ASCII range is available in fullwidth sizes that match the dimensions of the kanji and kana.

All topics

Text direction

Vertical text

Glyph shaping & positioning

Fonts & font styles

Context-based shaping & positioning

Letterform slopes, weights, & italics

Case & other character transforms

Typographic units

Characters & encoding

Grapheme/word segmentation & selection

Punctuation & inline features

Phrase & section boundaries

Quotations & citations

Emphasis & highlighting

Abbreviation, ellipsis & repetition

Inline notes & annotations

Text decoration & other inline features

Data formats & numbers

Line & paragraph layout

Line breaking & hyphenation

Text alignment & justification

Text spacing

Baselines, line height, etc.

Lists, counters, etc.

Styling initials

Page & book layout

General page layout & progression

Grids & tables

Footnotes, endnotes, etc

Page headers, footers, etc

Forms & user interaction