Romaji Converter

Romaji has several correct answers — and a new official one

Writing Japanese in the Latin alphabet sounds like a lookup, and a chart of a hundred-odd kana makes it look like one. It is not, because more than one system is in real use and they disagree. The same word can be maccha, matcha or mattya, and a person's name can appear one way in a library catalogue and another way in their passport. None of those spellings is a mistake. Each follows a rulebook, and the rulebooks were written for different jobs. This tool prints all of them side by side so you can see exactly where, and why, they part company.

The official standard changed on 22 December 2025

For more than seventy years the Japanese government's own spelling rules were a 1954 cabinet notice built on Kunrei-shiki: し as si, ち as ti, つ as tu, ふ as hu. Almost nobody outside a classroom wrote that way — road signs, passports, company names and textbooks for foreigners had long used Hepburn's shi, chi, tsu, fu. In August 2025 the government's advisory council on the national language recommended bringing the rules into line with that practice, and on 22 December 2025 a new cabinet notice replaced the 1954 one. The official spellings are now Hepburn-based.

For seventy-one years the government's official spelling of ち was ti. Since December 2025 it has been chi — the spelling almost everyone was already using.

Where "Hepburn" disagrees with itself

The new standard is Hepburn-based, not identical to every Hepburn you will meet. Three differences matter. A doubled ち is written cchi in the notice — its own examples are nicchoku and maccha — while dictionaries and library catalogues following the ALA-LC tables, and Japanese passports, write tchi. The syllable ん is always n in the notice (shinbun), where older Hepburn and passports write m before b, m and p (Shimbashi). And long vowels may take a macron (Tōhoku) or be written with the vowels doubled as they are in kana (Touhoku) — the notice permits both. It also says plainly that established spellings such as Tokyo, judo, matcha and Shimbashi, and people's own names, need not change.

Passports follow their own table

The Ministry of Foreign Affairs publishes the table used for passport names, and it is stricter still. Long O and U are not written at all, so 伊藤 is ITO and 大野 is ONO — except that a surname ending in a written お keeps both letters, as in SENOO. The long mark ー disappears (ニーナ is NINA). Loanword sounds are spelled kana by kana, so ティ is TEI and ファ is FUA, and V is not allowed: ヴァ becomes BA or BUA. A spelling such as OHNO is possible only by prior arrangement.

What kana alone cannot tell you

Two decisions depend on the word, not the letters. とうきょう is one long vowel twice, but おもう ("think") ends in two separate vowels, and こうし is kōshi as "lecturer" but koushi as "calf". No rule over kana can separate them, so the tool reads pairs as long by default, lists every pair it merged, and lets you switch. The same goes for は and へ, which are wa and e only when they are grammatical particles — the tool flags them rather than guessing.

Kunrei-shiki and Nihon-shiki are not wrong, just retired

Kunrei-shiki remains the basis of the ISO 3602 standard and fills half a century of Japanese school materials and official documents, so you will keep reading it. Its logic is tidy: the T row is ta ti tu te to because in Japanese those are one series. Nihon-shiki goes a step further and spells ぢ, づ and を as di, du and wo, which makes it the only one of these you can convert back to kana without ambiguity.

For learners across Southeast Asia

Much of the world's Japanese is learned in this region. The Japan Foundation's 2024 survey counted about four million learners outside Japan, with Indonesia second only to China at 732,914 and Thailand and Vietnam also in the top ten. A learner in Jakarta, Bangkok or Ho Chi Minh City meets every system on this page: Hepburn in the textbook, Kunrei in older Japanese-made materials, passport spellings on a colleague's documents, and now the 2025 standard on new signs. Knowing which rulebook a spelling follows is what stops one correct answer being marked wrong against another.