Terrain Elevation API

Access & limitsPublic, no key needed · Light▾

Open to everyone. A free API key from your profile raises the limits: send it in an X-API-Key header, or as api_key= in the address.

	5 minutes	Hour	Day
Without a key	30	300	2,000
With a key	150	1,500	10,000

Log in to create a free key on your profile page.

Every answer carries X-RateLimit-Remaining and X-RateLimit-Reset. Over a limit, the answer is error 429 with retry_after in seconds. Refused requests do not count.

Ground elevation at any point on land, in metres above mean sea level. It is the same lookup Altimeter Cloud uses for launch site altitude, and it is cheap enough that we offer it openly: no account, no key, and no database behind it, just two file reads per point from our tiered terrain store.

Parameters

Parameter	Required	Description
lat	yes (single)	Latitude in decimal degrees, -90 to 90.
lon	yes (single)	Longitude in decimal degrees, -180 to 180. lng is accepted as an alias.
points	batch	Up to 500 lat,lon pairs separated by semicolons. Replaces lat and lon. Invalid pairs are skipped and counted in skipped.

Response

Field	Description
elevation_m	Ground elevation in metres above mean sea level (EGM96 geoid), one decimal. Also given as elevation_ft.
has_data	true on land we hold data for. false at sea or where no data exists, in which case the elevation is returned as 0.
tier	Which layer of the store answered: ultra, fine, medium, coarse or none. See the resolution table below.
cell_arcsec, cell_m	The grid spacing of that layer, in arc seconds and in metres north to south. East to west cells are narrower by the cosine of the latitude.
datum, units	Always EGM96 mean sea level and metres, stated so a client never has to guess.

Example

curl "https://www.altimetercloud.com/fr/api/terrain/?lat=54.3765&lon=-2.9893"

{
  "success": true,
  "lat": 54.3765,
  "lon": -2.9893,
  "elevation_m": 83.4,
  "elevation_ft": 273.6,
  "has_data": true,
  "tier": "ultra",
  "cell_arcsec": 1,
  "cell_m": 31,
  "datum": "EGM96 mean sea level",
  "units": "metres"
}

Batch

curl "https://www.altimetercloud.com/fr/api/terrain/?points=54.3765,-2.9893;46.593,7.908;40.86,-119.07"

{
  "success": true,
  "count": 3,
  "skipped": 0,
  "datum": "EGM96 mean sea level",
  "units": "metres",
  "points": [
    { "lat": 54.3765, "lon": -2.9893, "elevation_m": 83.4, "elevation_ft": 273.6, "has_data": true, "tier": "ultra", "cell_arcsec": 1, "cell_m": 31 },
    { "lat": 46.593, "lon": 7.908, "elevation_m": 801.2, "elevation_ft": 2628.6, "has_data": true, "tier": "fine", "cell_arcsec": 3, "cell_m": 93 },
    { "lat": 40.86, "lon": -119.07, "elevation_m": 1191.0, "elevation_ft": 3907.5, "has_data": true, "tier": "ultra", "cell_arcsec": 1, "cell_m": 31 }
  ]
}

Errors

{ "success": false, "error": { "code": "412", "message": "Supply lat= and lon= in decimal degrees (lat -90 to 90, lon -180 to 180), or points=lat,lon;lat,lon" } }

{ "success": false, "error": { "code": "413", "message": "Too many points, the limit is 500 per request" } }

Resolution and accuracy

The store is built from 1 arc second (30 m) satellite elevation data, reduced into layers so that detail is kept where it matters and the whole of the world's land still fits on one server. Every value is the mean elevation of its cell, interpolated between the four cells around your point.

Tier	Cell	Where
ultra	1 arcsec, about 30 m	The whole of the UK and Ireland, the Alps, and within 10 km of known rocketry launch sites worldwide: the raw samples, nothing averaged.
fine	3 arcsec, about 90 m	The UK, EU, US, New Zealand, Japan, South Korea, Taiwan and Israel, and the steepest ground anywhere in the world.
medium	6 arcsec, about 185 m	Hilly ground elsewhere in the world.
coarse	18 arcsec, about 550 m	All remaining land: plains, deserts, tundra.

Heights are orthometric, that is metres above the EGM96 geoid (mean sea level). They compare directly with a barometric altitude, but sit 10 to 60 m away from a raw GNSS ellipsoid height. The underlying data has an absolute accuracy of roughly 5 to 10 m; on steep ground a cell mean can differ from the exact point by more, and on a flat field it is usually within a few metres. Sea reads 0. In the known depressions (the Low Countries, Death Valley, the Salton and Jordan valleys, the Caspian, Qattara, Turfan, Afar and a few others) land below sea level is reported at its true negative height, and sea close to those areas may read negative too.

Try it

Terrain data credits

The ground heights come from the Terrain Tiles dataset (Mapzen / Tilezen, on AWS Open Data), reduced into resolution tiers by Altimeter Cloud. Wherever you show heights from this API, credit their sources. Each answer carries a short form of the list below in its credits field.

• ArcticDEM terrain data DEM(s) were created from DigitalGlobe, Inc., imagery and funded under National Science Foundation awards 1043681, 1559691, and 1542736
• Australia terrain data © Commonwealth of Australia (Geoscience Australia) 2017
• Austria terrain data © offene Daten Österreichs – Digitales Geländemodell (DGM) Österreich
• Canada terrain data contains information licensed under the Open Government Licence – Canada
• Europe terrain data produced using Copernicus data and information funded by the European Union - EU-DEM layers
• Global ETOPO1 terrain data U.S. National Oceanic and Atmospheric Administration
• Mexico terrain data source: INEGI, Continental relief, 2016
• New Zealand terrain data Copyright 2011 Crown copyright (c) Land Information New Zealand and the New Zealand Government (All rights reserved)
• Norway terrain data © Kartverket
• United Kingdom terrain data © Environment Agency copyright and/or database right 2015. All rights reserved
• United States 3DEP (formerly NED) and global GMTED2010 and SRTM terrain data courtesy of the U.S. Geological Survey

The licences behind each statement are on the terrain tiles attribution page.