4

You mean "OpenTopoMap tiles", not "data". You can render your own with their open-source style from https://github.com/der-stefan/OpenTopoMap That would be the nicest and most independent way. You could mass-download their tiles with any suitable tool or script, but please ask them before for permission and rate-limits, see https://opentopomap.org/credits


Only top voted, non community-wiki answers of a minimum length are eligible