#gis

UTM ↔ geographic coordinate conversion as an API, computed locally and deterministically on the WGS84 ellipsoid. The from-latlon endpoint projects a latitude and longitude into the Universal Transverse Mercator grid — returning the zone (1–60), the hemisphere, the latitude band letter, and the easting and northing in metres — using the Snyder/USGS Transverse Mercator series, which is accurate to a few millimetres within a zone; New York (40.7128, −74.0060) maps to zone 18N at about 583960 E, 4507351 N, and the canonical 45°N on a central meridian gives a northing of exactly 4982950.40 m. The to-latlon endpoint inverts it, recovering the latitude and longitude from a zone, hemisphere, easting and northing. Each zone is 6° of longitude wide with a 500000 m false easting on its central meridian and a 10000000 m false northing in the southern hemisphere. Latitude is valid from −80° to 84°. Everything is computed locally and deterministically, so it is instant and private. Ideal for GIS, surveying, mapping, geospatial, drone-mapping and location app developers, coordinate-conversion and grid-reference tools, and spatial software. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 2 endpoints. This is UTM on WGS84; for the polar regions use UPS and for an EPSG-code lookup use an EPSG API.

api.oanor.com/utm-api

Advanced geodesy beyond the simple great circle. The vincenty endpoint computes the distance between two latitude/longitude points on the WGS84 ellipsoid using Vincenty's inverse formula — accurate to within a millimetre, far better than the spherical approximation — plus the initial and final bearings, in metres, kilometres, miles and nautical miles. The rhumb endpoint computes the rhumb-line (loxodrome) distance and the single constant compass bearing that follows it — the path you steer by holding a heading, as used in marine and air navigation. The cross-track endpoint finds how far a point lies to the left or right of a great-circle path between two points (the cross-track distance) and how far along that path it is (the along-track distance). Everything is computed locally and deterministically, so it is instant and private. Ideal for marine and aviation navigation, surveying and GIS, route analysis, and precise mapping. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 4 endpoints. This is advanced geodesy; for simple great-circle distance, bearing, midpoint and destination use a geo-distance API and for coordinate-format conversion use a geo-convert API.

api.oanor.com/geodesy-api

Convert geometry between WKT (Well-Known Text) and GeoJSON, in both directions. WKT is the textual geometry format used by PostGIS, Spatialite, GEOS, JTS, Shapely and the OGC Simple Features standard (POINT (30 10), LINESTRING (...), POLYGON ((...))); GeoJSON is what web maps and JavaScript expect. The to-geojson endpoint turns a WKT string into a GeoJSON geometry, and to-wkt does the reverse from a GeoJSON geometry or Feature. Supports Point, LineString, Polygon, MultiPoint, MultiLineString, MultiPolygon and GeometryCollection. Perfect for bridging a spatial database and a front-end map, importing and exporting geometry, and data-migration scripts. Pure local computation — no key, no third-party service, instant; send large geometries via POST. Live, nothing stored. 3 endpoints. Distinct from coordinate-format conversion, EPSG/CRS lookups, slippy map tiles and GeoJSON geospatial metrics.

api.oanor.com/wkt-api

Measure GeoJSON geometry on the surface of the earth. Compute the true area of a Polygon or MultiPolygon (in square metres, square kilometres, hectares, acres and square miles), find the centroid of any GeoJSON, get the bounding box (west/south/east/north) and its centre, measure the length of a LineString or MultiLineString (in kilometres, metres, miles and nautical miles), and test whether a latitude/longitude point falls inside a polygon. Accepts geometries, Features and FeatureCollections; coordinates follow the GeoJSON [longitude, latitude] order. Perfect for mapping apps, geofencing, territory and catchment analysis, route distances and spatial dashboards. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 6 endpoints. Distinct from abstract shape geometry, coordinate-format conversion, slippy map tiles and administrative-boundary data.

api.oanor.com/geojson-api

The maths behind every web map. Convert between latitude/longitude, slippy-map XYZ tile coordinates (the z/x/y scheme used by OpenStreetMap, Google Maps, Mapbox and Leaflet) and Bing/Azure quadkeys, and get the exact Web Mercator (EPSG:3857) bounding box and centre of any tile. Find which tile contains a point at a given zoom, expand a tile to its geographic bounds, translate a quadkey to z/x/y and back, and list a tile's eight neighbours (with correct antimeridian wrap-around and pole clamping). Perfect for tile servers and caches, pre-fetching map tiles, drawing tile grids and debugging map layers. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 5 endpoints. Distinct from coordinate-format conversion (Plus Code/MGRS/UTM), geohash and the encoded-polyline codec.

api.oanor.com/maptile-api

Convert geographic coordinates between every common format. Turn a latitude/longitude pair into a Plus Code (Open Location Code, as used by Google Maps), an MGRS reference (Military Grid Reference System), a UTM coordinate (zone, hemisphere, easting, northing) or a DMS string (degrees-minutes-seconds) — and convert any of those back to latitude/longitude. The /v1/all endpoint returns every format at once. Each conversion runs fully locally (no third-party service) so responses are instant and always available. Live, no cache. 6 endpoints. Built for GIS, mapping, surveying, logistics, aviation, emergency services and any app that exchanges coordinates between systems. Complements geohash and CRS lookups without overlap. No upstream key.

api.oanor.com/geoconvert-api

Map projections and coordinate reference systems as an API — the EPSG dataset made queryable. Every CRS, from geographic systems like WGS 84 (the GPS standard, EPSG 4326) to projected ones like Web Mercator (3857), the UTM zones and national grids, has an EPSG code. Search the dataset by name to find the code you need, then resolve any code to its full definition: name, kind (geographic, projected, …), area of use, scope, and — most usefully — the ready-to-paste PROJ.4 string and WKT definition that GIS libraries (GDAL, PROJ, PostGIS, Leaflet, OpenLayers, QGIS, GeoPandas) consume directly. Search comes from the official EPSG Registry maintained by IOGP; the PROJ.4/WKT exports come from epsg.io. A geodesy / coordinate-reference-system resource — distinct from geocoding (addresses to coordinates), geohashing and administrative-boundary APIs. Ideal for GIS, mapping, surveying, remote-sensing and spatial-data applications.

api.oanor.com/epsg-api

Open administrative boundaries as an API, powered by geoBoundaries — the open database of political administrative boundaries built by the William & Mary geoLab. For more than 200 countries and every administrative level — ADM0 (national), ADM1 (states, provinces or regions), ADM2 (counties or districts) and on down to ADM4/ADM5 local units — get the boundary's metadata (official name, the source agency that produced it, the data licence, the year represented, the number of administrative units and the mean vertex count) together with direct download links to the geometry in full-resolution GeoJSON, a simplified GeoJSON, TopoJSON and a ZIP bundle; list every administrative level available for a country with its unit count and download link; and browse the full catalogue of countries that have boundaries. The geometry itself is delivered as standard GeoJSON/TopoJSON files at the returned URLs, ready to drop into Leaflet, Mapbox, QGIS, deck.gl or any GIS pipeline. Ideal for mapping and visualisation, choropleths, spatial joins, geofencing, election and census cartography and location analytics. ISO codes are 3-letter (DEU, USA, BRA); administrative levels are ADM0 to ADM5. Data from the geoBoundaries project (CC-BY 4.0).

api.oanor.com/geoboundaries-api

Classify any location's climate with the Köppen-Geiger system — the standard used across geography, ecology, agriculture and architecture. Provide a location's twelve monthly mean temperatures and precipitation totals and get back its climate code (for example Cfb or BWh), the climate group and full name, a description, and a block of derived statistics (annual mean temperature, annual precipitation, warmest and coldest month, driest month, months above 10 °C, summer-precipitation share and the aridity threshold). The hemisphere is auto-detected from the temperature curve, or you can set it explicitly. A reference endpoint returns all thirty Köppen-Geiger codes with names, groups, descriptions and example cities. Every endpoint accepts input via the query string or the request body and returns lean JSON. Pure server-side computation (no third-party upstream), so responses are instant and always available. Ideal for EdTech and geography tools, AgTech and crop-suitability apps, architecture and GIS pipelines.

api.oanor.com/climate-api