Map data & licences

Topovelo draws none of its own maps. Everything you see comes from national mapping agencies and from OpenStreetMap, and each of them sets terms for being credited. This is the full list, in one place.

Last updated 1 September 2026

Netherlands

Topographic maps (TOPraster and TOP10NL) and aerial imagery from PDOK.
Kaart © Kadaster, used under CC BY 4.0.

The regional cycle-network overlay (Fietsnetwerk) is also served through PDOK, as is the regional walking-network overlay (Wandelnetwerk), which comes from the Landelijke Routedatabank.

United Kingdom

Leisure and Outdoor mapping from the Ordnance Survey Data Hub.
Contains OS data © Crown copyright and database right 2026.

Zürich

Maps and aerial imagery from the Federal Office of Topography.
© swisstopo, used under the terms for free geodata and geoservices.

Junction network and routing

This is the part that is easy to overlook, because it is not a picture. The Dutch knooppunten network, the junction numbers on the map, the routes computed for both the Netherlands and Zürich, and the places shown along a walk — water, benches, toilets, cafés, shelters — all come from OpenStreetMap data.

Junctions, routing & places © OpenStreetMap contributors, available under the Open Database Licence (ODbL).

Satellite imagery

The optional satellite layer outside Switzerland is Esri's World Imagery.
Imagery © Esri, Maxar, Earthstar Geographics, and the GIS User Community.

Rain radar and forecast

The rain layer shows the latest radar image from RainViewer, which combines weather radars from around the world.
Radar © RainViewer.

The forecast for the next two hours comes from Open-Meteo, which builds on national weather services' models.
Weather data by Open-Meteo.com, available under CC BY 4.0.

Address and place search

Dutch addresses come from PDOK's Locatieserver; Swiss places from geo.admin.ch.

Software

The map is drawn with Leaflet, with Proj4js and Proj4Leaflet for the Dutch and British national coordinate systems. These are served from this site rather than from a public CDN, so that using the map does not hand your address to a third party and so that it still opens without a connection.

Something wrong in the map itself?

Errors in the underlying data are best fixed at the source, where the correction reaches everyone rather than just this app: Dutch topography via Verbeter de Kaart, and junctions or cycle routes via OpenStreetMap.