Address to ZIP JA EN My Page

Find any Japanese postal code.

Type an address — kanji, kana, or romaji. Backed by Japan Post official data.

  • Japan Post official data
  • Updated monthly
  • Free, no sign-up
Data updated — — postal codes

Building an app? There is an API that converts both ways — address to postal code and back.

See the developer API

124,147

Postal codes covered

Monthly

Synced with official data

Two-way

Address ⇄ postal code

Why Address to ZIP

Japanese addresses are hard. We handle them.

Official data, updated monthly

We track Japan Post's monthly updates automatically — no CSV downloads, no re-imports, no stale postal codes. The data timestamp is public.

Romaji in, romaji out

Search with romanized input like “Marunouchi, Chiyoda-ku, Tokyo”, including spelling variants (Shimbashi/Shinbashi, Ōsaka/Osaka). Responses include romanized fields based on Japan Post's official romanization.

Integrate in minutes

Sign up and get an API key on the spot. 14-day free trial, nothing to install — a plain HTTPS API that works from any language.

API for developers

Drop it into your app or service.

A two-way API between Japanese addresses and postal codes. Your key is issued instantly at sign-up, with a 14-day free trial. Synced monthly with Japan Post official data.

curl --get "https://addresstozip.jp/api/v1/search" \
  --data-urlencode "address=Marunouchi, Chiyoda-ku, Tokyo" \
  -H "x-api-key: YOUR_KEY"
  • Address → postal code and postal code → address
  • Romanized fields (romaji) in every result — safe for Latin-1 systems
  • Accepts kanji, kana, and romaji input with spelling-variant matching
  • No monthly request cap, no restrictions on commercial use
  • Email + checkout is all it takes. Integrate in minutes

About the API Documentation