Hepburn romanization

thumb|upright=1.35|Chart of [[kana and their Hepburn romanizations, including both hiragana (roman) and katakana (italicized)|class=skin-invert-image]]

Hepburn (, ) is the main system of romanization for the Japanese language. The system was originally published in 1867 by American Christian missionary and physician James Curtis Hepburn as the standard in the first edition of his Japanese–English dictionary. The system is distinct from other romanization methods in its use of English orthography to phonetically transcribe sounds: for example, the syllable () is written as ' and () is written as ', reflecting their pronunciation in English (compare to ' and ' in the more systematic Nihon-shiki and Kunrei-shiki systems).

In 1886, Hepburn published the third edition of his dictionary, codifying a revised version of the system that is known today as "traditional Hepburn". A version with additional revisions, known as "modified Hepburn", was published in 1908.

Although Kunrei-shiki was the style favored by the Japanese government for 70 years, Hepburn remained the most popular method of Japanese romanization. Recognizing this fact, on December 22, 2025, the Japanese government officially adopted Hepburn, making it the standard romanization system for the country.

It is learned by most foreign students of the language, and is used within Japan for romanizing personal names, locations, and other information, such as train tables and road signs. Because the system's orthography is based on English phonology instead of a systematic transcription of the Japanese syllabary, individuals who do not speak Japanese and know English phonology will generally be more accurate when pronouncing unfamiliar words romanized in the Hepburn style compared to other systems. He published a second edition in 1872 and a third edition in 1886, which introduced minor changes. The third edition's system had been adopted in the previous year by the , a group of Japanese and foreign scholars who promoted a replacement of the Japanese script with a romanized system.

Hepburn romanization, loosely based on the conventions of English orthography (spelling), stood in opposition to Nihon-shiki, which had been developed in Japan in 1881 as a script replacement. However, the notation requires further explanation for accurate pronunciation by non-Japanese speakers: for example, the syllables and , which are written as ' and ' in Hepburn, are rendered as ' and ' in Nihon-shiki.

After the Russo-Japanese War of 1904–1905, the two factions resurfaced as the , which supported Hepburn's style, and the , which supported Nihon-shiki. The directive had no legal force, however, and a revised version of Kunrei-shiki was reissued by cabinet ordinance on December 9, 1954, after the end of occupation.

Although it lacked de jure status, Hepburn remained the de facto standard for multiple applications in Japan. As of 1977, many government organizations used Hepburn, including the Ministry of International Trade and Industry; the Ministry of Foreign Affairs requires the use of Hepburn on passports, and the Ministry of Land, Infrastructure and Transport requires its use on transport signs, including road signs and railway station signs. According to a survey by the Japanese Agency for Cultural Affairs in 2022, the Japanese primarily used Hepburn to spell place names.

Hepburn is also used by private organizations, including The Japan Times and the Japan Travel Bureau.

American National Standard System for the Romanization of Japanese (ANSI Z39.11-1972), based on modified Hepburn, was approved in 1971 and published in 1972 by the American National Standards Institute.

On December 16, 2025, the Japanese government decided to issue a cabinet notification on December 22 revising national rules on romanization for the first time in about 70 years, making the Hepburn system the standard instead of Kunrei-shiki.

Variants

thumb|250px|Former [[Japan National Railways–style board of Toyooka Station. For the two adjacent stations, "GEMBUDŌ" follows the Hepburn romanization system, but "KOKUHU" follows both the Nihon-shiki and Kunrei-shiki systems.]]

There are many variants of the Hepburn romanization. The two most common styles are as follows:

Traditional Hepburn, as defined in various editions of Hepburn's dictionary, with the third edition (1886) often considered authoritative (although changes in kana usage must be accounted for). It is characterized by the rendering of syllabic as before the consonants b, m and p: for example, for .
Modified Hepburn, also known as Revised Hepburn, in which (among other changes) the rendering of syllabic as before bilabial consonants is no longer used: ' for . The version of the system published in the third (1954) and later editions of Kenkyusha's New Japanese-English Dictionary are often considered authoritative; it was adopted in 1989 by the Library of Congress as one of its ALA-LC romanizations, and is the most common variant of Hepburn romanization used today.

In Japan itself, there are some variants officially mandated for various uses:

, which mostly follows Modified Hepburn, except syllabic is rendered as in Traditional. Japan Railways and other major railways use it for station names.
, used for road signs, which otherwise follows Modified Hepburn closely but specifies that macrons are not to be used.
, a permissive standard that renders the syllabic as before b, m and p. Most of the long vowels are not rendered, and macrons are not used above the letter. Moreover, this standard explicitly allows the use of in personal names with special approval, notably for passports. In particular, the long vowel ō can be romanized , or (, or for ).

Details of the variants can be found below.

Obsolete variants

The romanizations set out in the first and second versions of Hepburn's dictionary are primarily of historical interest. Notable differences from the third and later versions include:

Second version

and were written as : Yedo
and were written as : kudzu, tsudzuku
, , and were written as , and
(modern: ) was written as : Kuwannon, kuwaidan

First version

The following differences are in addition to those in the second version:

was written as .
was written as .
and were written as .

Features

The main feature of Hepburn is that its orthography is based on English phonology. More technically, when syllables that are constructed systematically according to the Japanese syllabary contain an "unstable" consonant in the modern spoken language, the orthography is changed to something that better matches the real sound as an English-speaker would pronounce it. For example, is written not . This transcription is thus only partly phonological.

Some linguists such as Harold E. Palmer, Daniel Jones and Otto Jespersen object to Hepburn, contending that the pronunciation-based spellings can obscure the systematic origins of Japanese phonetic structures, inflections, and conjugations. Since the vowel sounds in Hepburn are similar to the vowel sounds in Italian, and the consonants similar to those of many other languages, in particular English, speakers unfamiliar with Japanese will generally be more accurate when pronouncing unfamiliar words romanized in the Hepburn style compared to other systems.

Long vowels

In Hepburn, vowel combinations that form a long sound are usually indicated with a macron (◌̄). Other adjacent vowels, such as those separated by a morpheme boundary, are written separately:

{|class="wikitable"

|+ Vowels part of the same morpheme

!in traditional Hepburn

!in modified Hepburn

!A + A

|aa: – 'grandmother' (ba + a)

|ā: – 'grandmother' (ba + a)

!I + I

| colspan="2" |ii: – Niigata (city)| (ni + i)

!U + U

| colspan="2" |ū: – 'mathematics' (su + u)

!E + E

|ee: – 'older sister' (ne + e)

|ē: – 'older sister' (ne + e)

!O + O

| colspan="2" |ō: – 'detour' (to + o)

!O + U

| colspan="2" |ō: – 'study' (kyo + u)

{|class="wikitable"

|+Vowels part of separate morphemes

!In traditional

– indicated with an h (only applies after o). This is sometimes known as "passport Hepburn", as the Japanese Foreign Ministry has authorized (but not required) it in passports.
– written using kana spelling: ō as ou or oo (depending on the kana). This is also known as style, as it reflects how text is entered into a Japanese word processor by using a keyboard with Roman characters. more accurately represents the way that ō is written in kana by differentiating between (as in (), in ) and (as in (), in ); however, it fails to differentiate between long vowels and vowels separated by a morpheme boundary.
– written by doubling the long vowels. Some dictionaries such as the Pocket Kenkyusha Japanese Dictionary and Basic English Writers' Japanese-English Wordbook follow this style, and it is also used in the JSL form of romanization.

Particles

In traditional and modified:

When is used as a particle, it is written .

In traditional Hepburn:

When is used as a particle, Hepburn originally recommended .).
When is used as a particle, it is written . In modern Hepburn romanization, they are often undefined. Katakana combinations with beige backgrounds are suggested by the American National Standards Institute and the British Standards Institution as possible uses. Ones with purple backgrounds appear on the 1974 version of the Hyōjun-shiki formatting.