What is the difference between the three schemes?

Hepburn writes sounds as English speakers hear them (し = shi, ち = chi, つ = tsu). Nihon-shiki is the most systematic, mapping each kana by its grid position (し = si, ぢ = di). Kunrei-shiki is the Japanese government and ISO 3602 standard, a near-merge of Nihon-shiki that simplifies a few pairs (し = si, ぢ = zi).

How is the small っ handled?

The sokuon っ doubles the following consonant in all three schemes, so きって becomes kitte. Before ch in Hepburn it produces tch (まっちゃ = matcha), which is the standard Hepburn convention.

How are long vowels treated?

The katakana long mark ー repeats the preceding vowel, so コーヒー becomes koohii. Hepburn often uses a macron in print, but this tool repeats the vowel so the output stays plain ASCII and reversible.

Does it handle yōon like きゃ?

Yes. Combined kana such as きゃ, しゅ, ちょ are treated as single syllables and romanized accordingly — kya, shu, cho in Hepburn or kya, syu, tyo in Kunrei-shiki. The converter matches multi-character kana before single kana.

No. Conversion runs entirely in your browser using built-in tables. Nothing you enter is sent to a server.

Japanese Romaji Converter

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Convert kana to romaji in three schemes

Romaji is not one system. This converter transliterates hiragana and katakana into the three standard schemes — Hepburn, Nihon-shiki, and Kunrei-shiki — with correct handling of yōon, sokuon, and long vowels, so you can pick the right one for documents, search, or linguistics.

How it works

Each kana (longest match first, so yōon like きゃ are caught) is looked up in the table for the chosen scheme, then two rules adjust the output:

っ + か  →  kka   (sokuon doubles the next consonant)
ー        →  repeats the previous vowel (コーヒー → koohii)

Multi-character kana are matched before single kana so combined syllables romanize as one unit.
The sokuon っ doubles the following consonant; before Hepburn ch it yields tch.
The long-vowel mark ー repeats the preceding vowel; unknown characters pass through unchanged.

Example and notes

きょうとし becomes kyoutoshi in Hepburn and kyoutosi in Kunrei-shiki (し = si). ふじさん is fujisan in Hepburn but huzisan in both Nihon-shiki and Kunrei-shiki (ふ = hu, じ = zi). Choose Hepburn for general English-facing text and Kunrei-shiki for official or academic use. All conversion happens in your browser.