Japan Prefectures Boundaries — GeoJSON Download (47 Prefectures)
Quick answer: This page hosts all 47 Japanese prefectures as a single 170 KB GeoJSON FeatureCollection, with a browser map preview and one-click download under the Open Database License.
About this dataset
All 47 Japanese prefectures as one hosted GeoJSON, simplified from OpenStreetMap-derived boundaries to about 170 KB.
Download Japan prefecture boundaries as GeoJSON: all 47 prefectures in a single FeatureCollection carrying shapeName (Osaka Prefecture, Hyogo Prefecture, Oita, …), shapeISO, and shapeID. The source boundaries are OpenStreetMap-derived, compiled by the Wambacher project and published through geoBoundaries, and are simplified here to about a 1 km tolerance so the whole national layer stays around 170 KB. Because the geometry comes from OSM rather than a government boundary file, the prefecture names follow the source's mixed English and romanised Japanese conventions — some carry the 'Prefecture' suffix and some do not — so match on shapeISO rather than on the name string if your join table is strict.
Data source: OpenStreetMap via Wambacher / geoBoundaries
How to download
- 1 Preview the prefecture layer above — all 47 units render from one file.
- 2 Download the GeoJSON and open it in QGIS, ArcGIS, or GeoDataViewer Studio.
- 3 Join e-Stat or other Japanese statistical tables on shapeISO rather than the name string.
- 4 Use the full-detail file when you need precise island and coastline geometry.
FAQ
Are all 47 prefectures included?
Yes, all 47 — the 43 standard prefectures plus the two urban prefectures (Osaka and Kyoto), Hokkaido, and Okinawa.
Why do some names include 'Prefecture' and others not?
The source is OpenStreetMap-derived and its English naming is inconsistent. Match on shapeISO when your join table is strict, or normalise both sides by stripping the word 'Prefecture' before comparing.
What licence applies?
The boundaries are OpenStreetMap-derived and carry the Open Database License (ODbL 1.0). That permits commercial use but requires attribution to OpenStreetMap contributors and share-alike terms for derivative databases — read the ODbL before redistributing a modified boundary set.
Is a government boundary source available instead?
Yes. Japan's Geospatial Information Authority (GSI) publishes official administrative boundary data. This hosted layer uses the OSM-derived source because it is globally consistent with the rest of the geoBoundaries set.