OpenAddresses is a free and open collection of postal address data around the world. Currently OpenAddresses has a lot of address data in the USA, Japan, Belgium, Australia and Denmark, with patchy coverage elsewhere.
Open Addresses has visualized the current coverage of address data worldwide on a Mapbox created map. This dot map of open addresses represents each open address in the collection as a white dot. This allows you to zoom in on town and cities to see if open addresses are available to download at your location.