Plus Codes grid

Open Location Code (Plus Codes), an open standard from Google that encodes a location as a short alphanumeric code. Codes are hierarchical: each extra pair of characters refines the cell by a factor of 20, giving an address-like reference anywhere.

The interactive explorer below is rendered with deck.gl and behaves like the h3geo.org map: the Plus Code precision follows the zoom and codes are generated in the browser for whatever is in view. Two neighbouring precisions are shown at once — the current level with a darker, heavier border and the next finer level with a lighter, thinner one. Plus Codes subdivide 20×20 per level, so the next finer preview only fits once you have zoomed in. The base-20 encoder is the exact one in m3s.pluscode, reproduced in JavaScript so the codes and edges match M3S. GIS-native (lon, lat) order is used throughout.

Why Plus Codes?

Plus Codes are street addresses for places that have none: 8FW4V75V+8Q identifies a building entrance anywhere on Earth, works offline, carries no licensing, and Google Maps resolves it directly — which is why it is used for deliveries and services in informally addressed areas. That is the use case; as an indexing or analysis grid it is unremarkable (latitude/longitude rectangles, a steep ×400 jump between precision levels). For database range queries prefer Geohash grid; for aggregation and statistics, H3 grid or EA-Quad grid.

Usage

Encode a point and tile a small bounding box around Paris — same result in Python and JavaScript (both call the shared core):

Python

import m3s

cell = m3s.PlusCode.from_geometry((2.35, 48.86))            # (lon, lat)
cells = m3s.PlusCode.from_geometry((2.2, 48.8, 2.4, 48.9))  # bbox
print(cell.id, len(cells))

JavaScript

import * as m3s from "m3s";
await m3s.ready();

const cell = m3s.PlusCode.fromPoint(2.35, 48.86);            // (lon, lat)
const cells = m3s.PlusCode.fromBbox([2.2, 48.8, 2.4, 48.9]); // bbox
console.log(cell.id, cells.length);

from _deckmap import DeckExplorer, read_grid_js


DeckExplorer(
    center=(9.5, 48.5),
    zoom=5,
    grid_js=read_grid_js("pluscode"),
    hover="#AA4499",
    wasm=True,
)