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
* You can input Hiragana, Katakana, and spaces
📄 Result
🔒 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
What is the Romaji Converter?
The Romaji Converter is a free online tool that automatically converts Hiragana and Katakana to Hepburn and Kunrei-shiki romanization. It is ideal for passport applications and credit card name verification.
Who is this for?
People verifying romanized names for passport applications, those checking credit card name spellings, anyone comparing Hepburn and Kunrei-shiki romanization differences, and those preparing documents requiring romanized Japanese.
Key Features
- Supports both Hepburn and Kunrei-shiki romanization with side-by-side results
- Accepts both Hiragana and Katakana input
- Completely free with no registration required
- All processing is done in your browser - no data is sent to any server
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.
This tool only supports Hiragana and Katakana. Please convert Kanji to Hiragana first.
No, all processing is done in your browser. Your input data is never sent to a server.
It's completely free with no usage limits. No user registration is required.
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