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About coordlab.app

Sources, accuracy and privacy.

Accuracy is the product

Every system is tested against control points published by the country's official agency: Ordnance Survey, the US National Geodetic Survey, Geoscience Australia, LINZ, IBGE, swisstopo, Lantmäteriet, Japan's GSI and others. Projections agree to the millimetre.

Where the agency publishes an official correction grid, the converter uses it: OSTN15 in Great Britain, RDNAPTRANS™2018 in the Netherlands, BeTA2007 in Germany, CHENyx06 in Switzerland, IBGE's ProGriD in Brazil, SPED2ETV2 in Spain, gr3df97a in France, LINZ's grid in New Zealand and the JHS 197 triangle network in Finland. Only the grid for your point is downloaded, when it is needed. Elsewhere, datum changes use the 3- or 7-parameter transformation published by the agency. Each result shows the accuracy of the method applied, for example ±0.03 m.

Privacy

Everything is calculated in your browser: coordinates and spreadsheets are never sent to a server. The map only downloads OpenStreetMap tiles when it is on screen. Your theme and decimal-separator preferences are stored only on your device.

We count visits anonymously with Umami, without cookies: only the page, the referring site, the approximate location, the language, the browser, the operating system and the device type are recorded. The coordinates and data you type are never sent.

Visits are counted with Google Analytics, which stores cookies in your browser and receives the page address without coordinates. What you type, convert or upload is not sent to it.

Sources and licences

  • Projections: proj4js (MIT), with definitions from the EPSG registry.
  • Geodesics and areas: GeographicLib by Charles Karney (MIT).
  • MGRS: the mgrs library (MIT). Plus Codes: Google's open specification (Apache 2.0).
  • Map: Leaflet (BSD) and data © OpenStreetMap contributors (ODbL).
  • Cities: GeoNames (CC BY 4.0).
  • Transformation parameters: Ordnance Survey, NGS, ICSM, LINZ, IBGE, swisstopo, ČÚZK, Lantmäteriet, JHS 197 (Finland), Survey of Israel and others, cited on each system page.
  • Official datum grids, via PROJ-data: Ordnance Survey OSTN15 (BSD 2-Clause, © Crown copyright), IBGE ProGriD SAD69, SAD96 and CA7072 (CC BY-SA 4.0), IGN España SPED2ETV2 (CC BY 4.0), NSGI RDNAPTRANS™2018 (CC BY 4.0), AdV BeTA2007, swisstopo CHENyx06 (CC0), IGN France gr3df97a (Licence Ouverte), LINZ NZGD2000 (CC BY 4.0) and the Maanmittauslaitos JHS 197 triangle network (CC BY 4.0).
  • Additional official grids and triangle networks: DGT © 2019 (D73_ETRS89_geo, DLx_ETRS89_geo); SDFI (s34j_2022, s34s_2022); Kartverket (ETRS89NO_NGO48_TIN); LĢIA (LKS92to2020NTv2); LMÍ (ISN93_ISN2016, © 2017–2019 Guðmundur Valsson), PROJ-data; GURS (D48/GK → D96/TM v4.0), e-prostor. CC BY 4.0. File format converted; original licence retained.
  • Required attribution for the GeoSN grid: Datenquelle: Landesamt für Geobasisinformation Sachsen (GeoSN), NTv2_SN, dl-de/by-2-0; Daten verändert. File format converted; original licence retained.
  • NOAA National Geodetic Survey, NADCON 2.1 (CONUS, Alaska): Public domain (US federal government work). NOAA / PROJ-data. File format converted; original licence retained.
  • NS778302 — Nova Scotia Geomatics Centre / Natural Resources Canada: Contains information licensed under the Open Government Licence – Canada. Open Government Licence – Canada. File format converted; original licence retained.
  • Zone boundaries and areas of use: EPSG Geodetic Parameter Dataset, IOGP (SPCS 27, SPCS 83, NADCON CONUS).