🗾 Lookups & Reference
Look up Japanese postal codes, municipalities and prefectures, pick prefectures interactively, and convert numbers into formal kanji numerals.
Reference lookups for addresses in Japan: postal codes to places, municipalities inside prefectures, and a picker for all 47 prefectures.
The kanji numeral converter writes amounts in the formal style used on contracts and receipts — daiji, the characters that cannot be altered with a single stroke.
Japan Municipality Lookup
Decode any Japanese 5-digit municipality code: the first two digits identify the prefecture, and the table below covers ordinance-designated cities, Tokyo wards and prefecture capitals with their codes.
Japan Postal Code Lookup
Enter any Japanese 7-digit postal code to validate its format, get the hyphenated form, and see which prefecture (都道府県) the first two digits belong to - instantly, in your browser.
Japan Prefecture Picker
Find any of Japan's 47 prefectures by name, kana, English name or JIS code. Each card shows the capital city and region, and you can filter by the 8 traditional regions.
Kanji Numerals Converter
Convert between Arabic numerals and Japanese kanji numerals in standard (一, 二, 百, 万) and formal banking (壱, 弐, 参) styles - bidirectional, instant.
Frequently asked questions
What is the Japanese postal code format?
Seven digits written 〒NNN-NNNN since 1998; the lookup ties a code to its prefecture, municipality and district readings.
Why convert numbers to formal kanji?
Legal and financial documents in Japan use daiji — 壱, 弐, 参 — precisely because they are hard to alter; the converter renders amounts in that style.
How are prefectures organized?
The standard 47 prefectures with their ISO codes and regions; the picker and lookups share the same structure.