住所正規化
This address normalizer and postal code search tool is a free utility for batch normalizing Japanese address data and searching addresses by postal code. Supports full-width/half-width unification, space removal, and prefecture addition/removal. All data is processed securely in your browser with no server transmission.
What You Can Do
The Address Normalizer & Postal Code Search tool allows you to batch normalize Japanese addresses or search addresses by postal code, all within your browser. Perfect for customer database unification, Excel data cleansing, and mailing list preparation. Execute complex conversions like full-width/half-width unification, space removal, and kanji-to-Arabic numeral conversion with one click.
- ✅ Postal Code Search: Auto-fill prefecture, city, and town from postal code
- ✅ Batch Normalization: Process multiple addresses at once, standardize inconsistent notations
- ✅ Browser-based: No data sent to servers, secure processing
郵便番号から住所を自動入力、表記ゆれを統一。全角・半角、都道府県の有無などを一括で整形。データクレンジングに便利。
🔍 Postal Code Search
* Hyphen is optional
📍 Search Result
🔒 All processing except postal code search is done in browser.
⚙️ Address Normalization
* You can enter multiple addresses separated by line breaks
✅ Normalized Result
🔒 All processing is done in browser. No data sent to servers.
💡 Use Cases
- Unify address notation in customer database
- Quickly input addresses from postal codes
- Cleanse address data in Excel or spreadsheets
- Fix inconsistent addresses from web forms
- Prepare mailing lists for direct mail campaigns
❓ FAQ
We use the free API from zipcloud.ibsnet.co.jp, which is based on official Japan Post data.
Address normalization is fully processed in your browser. Only postal code search uses an external API, but address data is not stored.
Yes, you can enter multiple addresses separated by line breaks for batch normalization. However, extremely large amounts may slow down your browser.
Currently, basic normalization (full-width/half-width, space removal, etc.) is supported. More advanced normalization such as street number standardization is under consideration for future updates.
📚 Technical Knowledge
📮 Postal Code Data Source (Official Japan Post Data)
The postal code search data used in this tool is based on the official postal code database provided by Japan Post. Here's an explanation of the data characteristics and reliability:
- Official Japan Post Source: Based on Japan Post's regularly updated "National List Data" (CSV format), supporting the latest administrative division changes.
- Postal Code System: Japanese postal codes consist of 7 digits (e.g., 100-0001), where the first 2 digits represent the region and the next 3 digits represent the delivery district.
- Multiple Delivery Points: A single postal code may correspond to multiple towns, so search results may show multiple addresses. This is normal behavior.
- Regular Updates: Postal code data is regularly updated to reflect new town additions and administrative changes (such as municipal mergers).
💡 The reason postal code search accuracy is not 100% is that newly constructed buildings and new lot numbers take time to be reflected in the postal code data. In such cases, we recommend selecting the closest postal code from search results or checking with other tools (such as Japan Post's official website).
🔤 Address Notation Standardization Rules (Kanji to Arabic numerals, full-width to half-width, etc.)
Japanese addresses can have different notations for the same location. Here are the rules this tool uses for standardization:
- Kanji and Arabic Numerals:
- Notation variation: "Tokyo-to Chiyoda-ku Chiyoda 1-chome" vs "Tokyo-to Chiyoda-ku Chiyoda 1-chome"
- Standardization rule: This tool provides optional unification to Arabic numerals (0-9), useful for database searches and roster creation.
- Full-width and Half-width Mix:
- Notation variation: "Tokyo-to" vs "Tokyo-to" (mix of full-width and half-width numbers)
- Standardization rule: Optional unification to full-width (standard in Japanese systems) or half-width.
- Spaces, Line Breaks, and Line Break Codes:
- Notation variation: "Tokyo-to Chiyoda-ku" (two spaces), "Tokyo-to Chiyoda-ku" (full-width space)
- Standardization rule: Remove all spaces or unify to single space.
- Prefecture Notation:
- Notation variation: Missing prefecture ("Chiyoda-ku Chiyoda 1-1"), duplicate prefecture ("Tokyo-to Tokyo-to Chiyoda-ku")
- Standardization rule: Auto-add if missing, remove duplicates. This tool allows optional addition/removal of prefectures.
- Old and New Character Forms:
- Notation variation: "Kumamoto-ken Yatsushiro-shi" vs "Kumamoto-ken Yatsushiro-shi" (old form "㐈")
- Note: This tool does not perform automatic conversion, but you can obtain standard notation by searching based on official Japan Post data.
📌 Particularly in customer databases, CRMs, and e-commerce delivery information, such notation variations prevent automatic postal code matching. Pre-normalizing with this tool significantly improves data quality.
💼 Use Cases for Address Normalization (Data Cleansing, CRM Integration)
Address normalization is not just a data formatting tool, but an important process that significantly impacts overall business processes. Here are specific use cases:
- Customer Database Unification:
- Customer data aggregated from multiple sales channels or stores often has the same customer's address registered in different notations.
- Example: "Taro" is registered via Sales A as "Tokyo-to Chiyoda-ku Chiyoda 1-chome 1-banchi" and via Sales B as "Tokyo-to Chiyoda-ku Chiyoda 1-1"
- Address normalization enables detection of such duplicates, facilitating customer information integration and master data creation.
- CRM/SFA System Integration:
- In CRM systems like Salesforce and HubSpot, normalized address data significantly improves map display and delivery optimization algorithm accuracy.
- Combined with postal code search functionality, human errors during input can be reduced.
- E-commerce Delivery Address Management:
- In online shopping, repeat customers commonly enter the same address in different formats. Discrepancies arise when checking "billing address" and "shipping address" for identity.
- Address normalization improves delivery efficiency and reduces delivery errors (misdelivery, non-delivery).
- Excel/Spreadsheet Data Cleansing:
- Customer data and sales reports accumulated over multiple years in text-based formats contain numerous notation variations.
- Batch normalizing with this tool before importing into CRM or DWH (Data Warehouse) improves data quality and analysis accuracy.
- Direct Mail Preparation:
- By coordinating with the post office's "postal code search system" and normalizing mailing list addresses, you can reduce return rates (failed deliveries).
- Verification and correction with this tool is essential as pre-processing for bulk mailings.
- Statistical and Marketing Analysis:
- When performing regional customer analysis or sales analysis, if addresses are not normalized, customers in the same region may be counted multiple times, reducing analysis accuracy.
- Address normalization → postal code conversion → latitude/longitude conversion enables advanced geographic analysis.
⚠️ Privacy: All processing in this tool is completed in your browser, and address information is never sent to servers. You can safely use it with data containing personal information.
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