Japan address toolkit

Two things everyone shipping to Japan needs: turn a full Japanese address (kanji) into a correctly ordered English label, and resolve postal codes to addresses — free, with an API. Competitors stop at zip→city; this converter handles the whole address.

Kanji address → English label

Free zip-code API (static, CORS, no key)

Shard files by the first 3 digits — fetch once, cache forever (data refreshes monthly):

EndpointGET https://japan-warehouse-logistics.org/address/v1/zip/<first3>.json
Examplefetch('/address/v1/zip/160.json').then(r=>r.json()).then(j=>j.zips['1600023']){"pref":"東京都","city":"新宿区","town":"西新宿","pref_ro":"Tokyo","city_ro":"Shinjuku-ku","town_ro":"Nishishinjuku",…}
Convert APIGET /address/api/convert.json?q=<URL-encoded address> — full converter as JSON (30 req/min, 500/day per IP)
Terms, short version: free, but pages/apps showing the data must link visibly to loreatec.jp — full text in the API terms. Postal data: Japan Post (no copyright asserted); romanization derived from Japan Post's roman file.

Batch tool: enrich a CSV of postal codes in your browser →