MapTiler is a map API service from Switzerland. They offer a designer that allows you to customize the map design. It is easy to integrate in your own application with SDKs for many platforms and iframes for simple websites.
European alternatives to Mapbox
Mapbox is a US-American maps API service that provides custom maps for all kinds of use cases. Mapbox uses OpenStreetMap and NASA map data, but also proprietary maps from other vendors.
This pages lists European Mapbox alternatives from companies based in a member state of the European Union (EU) or the European Free Trade Association (EFTA).
OpenCage is a map API service from Germany. They offer SDKs for multiple platforms and a iframe integration.
Geoapify is a German maps API service with many APIs for maps, addresses, route calculations and many more.
JawgMaps is a maps API service from France. The offer custom maps, routing and elevation profile data.
SmartMaps by YellowMap is a B2B map platform specifically designed for seamless integration into business applications. The core of the platform lies in its API services. It enables developers to create highly functional and data-compliant map applications with features like maps, geocoding, complex routing, and address autocompletion, all without tracking user data.
Maptoolkit is an API framework from Austria, for the development of geodata applications.