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ローマ字変換

A free tool that automatically converts Hiragana and Katakana to Romaji. Supports Hepburn (for passports) and Kunrei (Japanese standard) systems. Offers uppercase/lowercase conversion and batch processing for multiple lines. All processing happens locally in your browser - no data is sent externally. Available instantly without registration.

What You Can Do

Romaji Converter instantly converts Hiragana and Katakana to Romaji. Perfect for Hepburn (passport) and Kunrei (official Japanese system). All processing is done in your browser for complete privacy.

✅ Hepburn & Kunrei Support: Choose between Hepburn for passports and Kunrei for official documents
✅ Uppercase/Lowercase Options: Capitalize first letter or convert all to uppercase for various use cases
✅ Multiple Lines Support: Convert multiple names or addresses at once for improved efficiency

Convert Hiragana and Katakana to Romaji automatically. Supports Hepburn, Kunrei, and passport notation. Free and unlimited use without registration.

📝 Input

Hiragana/Katakana Input

* You can input Hiragana, Katakana, and spaces

Romanization System

Hepburn (for passport) Kunrei

Output Format

Capitalize first letter All uppercase

📄 Result

Romaji Output

🔒 All processing is done in your browser. No data is sent to servers.

💡 Use Cases

Verify Romaji notation for passport applications
English notation for international documents
Credit card name entry
Name input for flight bookings
Create signatures for English emails

📚 Japanese Romanization Systems

History and Background

Romaji (ローマ字) refers to systems for writing Japanese using Latin letters. Multiple systems were proposed during the Meiji period, but two standardized systems are primarily used today:

1. Hepburn System

Official Name: Revised Hepburn Romanization. Originated from the system developed by 19th-century missionary J.C. Hepburn
International Standard: Adopted by ISO 3602-1989. Ideal for international documents
Passport Standard: Japanese passports use Hepburn. Also recorded in alien registration documents
Examples: し→shi, ち→chi, つ→tsu, ふ→fu, じ→ji
Features: Designed for natural pronunciation by English speakers. Uses macrons (ō) for long vowels

2. Kunrei System

Official Name: Nippon-shiki (Japanese-style). Established by Ministry of Education ordinance in 1881. Aimed at domestic standardization
Systematicity: Based on Japanese phonological system with more logical and consistent design
Usage: Domestic standardized documents and school education. Limited international use
Examples: し→si, ち→ti, つ→tu, ふ→hu, じ→zi
Features: Represents basic phonological forms. May be difficult for foreigners to read

Official Passport Notation Rules

Legal Basis: Based on "Passport Law Enforcement Regulations" and Ministry of Foreign Affairs guidelines
Notation System: Uses Revised Hepburn. Uppercase is the standard
Long Vowels: Generally omitted (e.g., おお → OO). Some exceptions may apply
Sokuon (っ): Double the following consonant (e.g., さっぽろ → SAPPORO)
Hatsuon (ん): Usually "N". Becomes "M" before b, m, p (e.g., さんぽ → SAMPO)
Yōon (small や): Ignore small characters (e.g., きゃ → KYA, しゃ → SHA)
Note: Different notation may be allowed if applicant provides special reasons

Japanese Phonology and Romanization

Phonemic Contrast: Japanese consonants have three fundamental contrast systems: K-row (k), S-row (s/sh), T-row (t/ch)
Phonological Environment: The sound "し" is [ɕi] (single sound, not two syllables). Kunrei's "si" reflects this phonological structure
Yōon Phonology: "きゃ" is not phonologically き+や but a single long consonant fricative
Hatsuon Allophones: Has allophones depending on following sound environment. Reflected in Romanization (n/m/ng)

📚 Hepburn vs Kunrei Comparison

Hiragana	Hepburn	Kunrei
し	shi	si
ち	chi	ti
つ	tsu	tu
ふ	fu	hu
じ	ji	zi
しゃ	sha	sya
ちゃ	cha	tya

* Hepburn is used for passport applications

❓ FAQ

Passports use Hepburn romanization. Please select "Hepburn (for passport)".

Long vowel marks are generally omitted in passports (e.g., おおの → ONO). However, OH notation may be acceptable in some cases.

Usually "n", but becomes "m" before b, m, p (e.g., さんぽ → SAMPO). This tool uses "n" consistently.

This tool only supports Hiragana and Katakana. Please convert Kanji to Hiragana first.

📅 Last Updated: December 9, 2025 | 💬 Feedback: Suggestions & Comments