Proposed new tile layers that will be featured on the OSM website should follow the following guidelines. Anyone may propose new tile layers for consideration and any such proposed additional tile layers should be added to the proposals section of the Featured tile layers page.
The acceptance of an additional tile layer is not automatic and must be assessed on a case-by-case basis using the following criteria as a guide.
Internally supported. The service provider/author must be in favor of having their tile layer on the website.
Global scope and coverage. The proposed tile layer must cover the whole earth (well, except for the polar regions that are cut off because of the square Mercator projection).
Capable of meeting traffic demands. The proposed tile layer server/server farm must be capable of accepting the traffic volume from the OpenStreetMap website.
Reliable service. The proposed tile layer must be reliable in terms of uptime and availability.
Up-to-date data. Tile layers maintaining minutely updates are preferred, but update periods of up to two weeks may be acceptable depending on the content of the map. Tile layers intended for “debugging” must be generally no more than one day out of date.
Unique. The proposed tile layer should offer something unique in approach or execution. For example, this could be based on particular theme or created using a particular set of software/technology which is not currently represented.
Interesting. This hugely arbitrary criteria includes pleasing aesthetics, social significance and benefit, humour, timeliness, newsworthiness, appeal to the community, and many other arbitrary value judgements.
Non-commercial. Non-commercial services are preferred. However, commercial services which provide benefit to the community will be considered.
Free and Open. Free and Open stylesheets and tile rendering and serving stacks are preferred.