Data
| Data | How it is fetched | Coverage | Year | How the screen uses it |
|---|---|---|---|---|
| e-Stat census | The server calls the e-Stat API | 23 wards | The 2020 census, and the five-year population change rate of the 2025 preliminary count | Population, density, change, age structure |
| ODPT | The server calls the ODPT API | The top 50 stations by number of lines | Not shown on screen | Ridership per station |
| 不動産情報ライブラリ (REINFOLIB) | The server calls the REINFOLIB API | 8 wards (Chiyoda, Chuo, Minato, Shinjuku, Shibuya, Toshima, Meguro, Shinagawa), up to 5 records per ward | 2024 | Fetched, but not drawn on screen |
| Hazard map portal | The browser loads the tiles directly | The visible map area | Not shown on screen | The map overlay on the 「災害」 tab |
| CARTO | The browser loads the tiles directly | The visible map area | None | The background map |
Ward boundaries (tokyo-wards.geojson) |
Bundled in the repository | 23 wards | None | The ward boundary lines on the map |
Station list (tokyo-stations.geojson) |
Bundled in the repository | Station positions and line names | None | Station positions and line names (「同梱データ（出典未確認）」) |
How fetched data is handled
The server keeps data fetched from e-Stat, ODPT and REINFOLIB for 24 hours after fetching it. Of the ODPT data, only ridership figures that include alighting passengers are used. Stations of JR East, Keio, Odakyu and others are not in ODPT, so their ridership is 「データなし」. Values that e-Stat does not publish are shown as 「データなし」, never as 0.
The attribution shown on screen is listed in Data sources and attribution, and processing is described in Data sources and methods (Japanese).