Wikimedia Maps/2015-2017/Conversation about interactive map use

The Maps team of the Discovery department is working to figure out how to create tools for using interactive maps in Wikipedia articles. There are many things we want to include in this feature, and plan to develop the quality of interactive maps over time. For this initial work, we'd like to keep the focus on how maps can be used for articles where a map would show general geographic location information.

Example of an interactive map. You can zoom and pan.

Here we provide an overview of interactive maps, and are asking interested individuals to participate in a discussion around three major #Questions (open discussion outside these questions is welcomed too).


Maps provide a way to discover and learn about a place or an event. Making these maps interactive, where people can zoom, pan, and interact with points of interest, can further enrich the way we learn about the world. Other goals, are simplifying the tools used to add a map to an article, and reducing the need for complex image editing or geographic information system (GIS) tools.

Inspiration and ideas for discussing these conventions, come from earlier work within our communities. Particularly, from the English Wikipedia's WikiProject Maps/Conventions, French Wikipedia's Projet:Cartographie, German Wikipedia's Kartenwerkstatt/Hilfe, and others.

Current focusEdit

  • What types of articles will use interactive maps?
  • How do these articles differ in their requirements?
  • Are there any classes of articles whose map styling requirement is fundamentally in conflict with other article classes, thus requiring multiple styles?

Use casesEdit

See Maps/Future Plans for an existing list of possible use cases
  • Showing a city within a region
  • Showing a region within a country
  • Showing points-of-interest in a specific area (like say all the buildings surrounding a castle or monuments in a given area)


Please add any examples where an article would benefit from an interactive map

Here are a few selected wiki articles that could potentially benefit from interactive maps. Included are the first two static maps that appear in the article currently, and an example interactive map.

Lyon, FranceEdit

The first two static maps (one is collapsed by default) in the English article for Lyon, France. Both show current boundaries, at different 'zoom levels'. The last map is dynamic that may replace them.

Static map showing the location of France.
Blank administrative map of Rhône-Alpes for geo-location purpose, with regions and departements distinguished.
Map of Lyon, with city limits, used on an article about a monument.

St. Louis, MOEdit

Again, the first two maps are existing maps on the English article for St. Louis, Missouri, USA. The third is an interactive map of the same region.

Static map of the continental United States.
Static map of the state of Missouri.


When talking about interactive maps (and maps in general) we use words to describe features of the mapping tools.

  • Style: how to draw the map - colors, line thickness, fonts, etc.
  • Tiles: square image that represents a portion of a map at a given zoom level
  • Tile data: the data contained within a set of tiles (park benches, tree locations, house numbers, park names, building type (churches, government, etc.))
  • Zoom level: At what level of detail are we looking at a particular area on a map? Imagine this as "How high above the map am I looking?" Often measured as a number (e.g. zoom=12 - where 0=world view, and 18=highest zoom).

How interactive maps workEdit

A screenshot showing how the visual editor dialog for Kartographer appears when editing a map.
  • Wikimedia map servers download the full OSM database.
  • Tilerator service converts OSM data into vector tiles (mini databases), one for each tile location and for each zoom level, and saves them to a database. This takes a long time, and gets done right after downloading because it cannot be done on-demand.
  • Kartotherian web server creates PNG tiles, by applying styling to the vector tiles. The image generation is very fast, so it gets done on-demand, when a browser asks for it.
  • Wiki editors insert a map with either <maplink> (a link to a new window) or <mapframe> (embedded in the page).
    • Editors can also use the visual editor to insert a map with an interface for adding points-of-interest and polygons.
  • Both map tags may contain additional geojson overlays data. Geojson could include markers, lines, and polygons. Geojson may draw these elements in different styles and with popups. At this point, geojson may only be located inside the map tags.

How interactive maps are styledEdit

The interactive maps can be styled for different uses. As an example, articles could have one style for geography, and another for transit articles. Each style could add a significant maintenance and performance cost, therefore we try to limit the number of different styles in production.

Editor that are interested in helping to define the styles can use the open-source Mapbox Studio Classic to create a custom map style sheet (CartoCSS). Similar to CSS, these stylesheets allow you to define the properties of elements for a particular style - including variations between zoom levels (e.g. At zoom level 10, roads should be X in width, but at closer zooms Y.)

Follow these instructions to download the map style and the edit tool. It will allow you to visually change all aspects of the map. Ideally, you should submit your changes as pull requests via GitHub. See GitHub's how to fork or a more generic getting started guides for more info. Alternatively, you could email us your project.yml and all the .mss files, but it will make it harder to merge your changes.


These are features and map types we're aware of, but don't have a solution for.

  • Historical (how borders have changed over time as an example)
  • Multilingual (one interactive map of a region, with labels shown in the visitors preferred language).

Pros and Cons of interactive mapsEdit

Where, and when, should they be used? Where/when should they not be used?


  • less work to create for people who are not knowledgeable with GIS and mapping technology
  • scalable to more folks creating maps!
  • less work to update (map tiles are updated when data is updated)
  • interactive - gain further context by panning and zooming within a map
  • zoom - visibility and legibility of small labels


  • area features with fuzzy delimitation, such as mountain ranges, are notoriously not handled well by Openstreetmap
  • Openstreetmap's proposed feature for handling disputed territories adds a level of complexity
  • centrally controlled rendering style limits per-article creativity
  • may not translate well to non-digital formats, e.g. printing (you only get the default view which may be too limited or too cluttered)
  • may change in unexpected ways (not static)
  • takes longer for changes to go live
  • OpenStreetMaps uses Web Mercator projection for it's map tiles. Other projections are far better for specific uses (Polar regions as an extreme case)


Here is the focus for this discussion about interactive maps. Please respond on the talk page in the corresponding section.

  1. What types of articles would use interactive maps?
  2. How do these articles differ in their requirements?
    • e.g. an article about a city or a disaster location may have very different requirements than the article about deforestation in Amazon forests or articles about animals and their habitats.
  3. Are there any classes of articles whose map styling requirement is fundamentally in conflict with other article classes, thus requiring multiple styles?

More example articles with mapsEdit

Other Maps ServicesEdit

  • OpenStreetMap - a large open-source map community and the source of our data tiles
  • Mapbox - a gallery of styles using Mapbox (on top of OSM tile data)

See alsoEdit

OpenStreetMap information
Historical or unsorted