Areas to join to, for this session: a GeoJSON file of Polygon or MultiPolygon features. Each area is named by a property with a different value for each one (a name-like one first). It's added to Other, under “Your files”.
CSV, JSON, GeoJSON or a Joiner snapshot. You can also drop a file anywhere on the page.
Google Sheets: share with “Anyone with the link”. DataSF and other Socrata portals: a dataset or /resource/ link loads every row. Any CSV, JSON or GeoJSON link works if its site allows it.
/resource/