A map name specified in the model-level map_layer parameter
Basics
The map_layer_name parameter lets you associate a dimension with a TopoJSON or GeoJSON map layer. This lets users create map charts by charting the values in the dimension on the map layer. For example, to be able to chart data by US state, you could associate a dimension called "State" to the built-in map layer us_states. You could also chart data in a dimension called "Neighborhood" to a custom map of New York City neighborhoods.
If you are using a custom TopoJSON or GeoJSON map, you must specify the map layer in the LookML model by using the map_layer parameter.
Dimensions of type: zipcode automatically receive a map_layer_name of us_zipcode_tabulation_areas.
Built-in map layers
Looker includes the following built-in map layers:
countries — Accepts full country names, ISO 3166-1 alpha-3 three-letter country codes, and ISO 3166-1 alpha-2 two-letter country codes. If your data includes ISO 3166-1 alpha-2 country codes, using map_layer_name with the countries map is recommended to ensure that Looker interprets your data as country codes and not as state codes.
uk_postcode_areas — Accepts UK postcode areas (for example, L for Liverpool, RH for Redhill, or EH for Edinburgh).
us_states — Accepts full state names and two-letter state abbreviations.
us_counties_fips — Works on string fields that are five-character FIPS county codes for a US county. This layer works only on the interactive map.
us_zipcode_tabulation_areas — Works on string fields that are five-character US zip codes. Dimensions of type: zipcode automatically use the us_zipcode_tabulation_areas map layer.
Zip code regions are based on the 2010 zip code tabulation areas (ZCTAs), so this map layer does not include many zip codes, such as those assigned to P.O. boxes, that do not map directly to regions.
Example
dimension: state {
map_layer_name: us_states
sql: ${TABLE}.state ;;
}
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Hard to understand","hardToUnderstand","thumb-down"],["Incorrect information or sample code","incorrectInformationOrSampleCode","thumb-down"],["Missing the information/samples I need","missingTheInformationSamplesINeed","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14 UTC."],[],[],null,["# map_layer_name\n\n\u003cbr /\u003e\n\n| **Note:** New in Looker 22.14, you can use GeoJSON files for custom map layers defined in the [`map_layer`](/looker/docs/2512/reference/param-model-map-layer) parameter.\n\nUsage\n-----\n\n```\nview: view_name {\n dimension: field_name {\n map_layer_name: name_of_map_layer\n }\n}\n```\n\nBasics\n------\n\nThe `map_layer_name` parameter lets you associate a dimension with a TopoJSON or GeoJSON map layer. This lets users create [map charts](/looker/docs/2512/visualization-types#maps) by charting the values in the dimension on the map layer. For example, to be able to chart data by US state, you could associate a dimension called \"State\" to the built-in map layer `us_states`. You could also chart data in a dimension called \"Neighborhood\" to a custom map of New York City neighborhoods.\n\nIf you are using a custom TopoJSON or GeoJSON map, you must specify the map layer in the LookML model by using the [`map_layer`](/looker/docs/2512/reference/param-model-map-layer) parameter.\n\nDimensions of [`type: zipcode`](/looker/docs/2512/reference/param-dimension-filter-parameter-types#zipcode) automatically receive a `map_layer_name` of `us_zipcode_tabulation_areas`.\n\n### Built-in map layers\n\nLooker includes the following built-in map layers:\n\n- `countries` --- Accepts full country names, [ISO 3166-1 alpha-3](http://en.wikipedia.org/wiki/ISO_3166-1_alpha-3) three-letter country codes, and [ISO 3166-1 alpha-2](https://en.wikipedia.org/wiki/ISO_3166-1_alpha-2) two-letter country codes. If your data includes ISO 3166-1 alpha-2 country codes, using `map_layer_name` with the `countries` map is recommended to ensure that Looker interprets your data as country codes and not as state codes.\n\n- `uk_postcode_areas` --- Accepts [UK postcode areas](https://en.wikipedia.org/wiki/Postcodes_in_the_United_Kingdom#Postcode_area) (for example, `L` for Liverpool, `RH` for Redhill, or `EH` for Edinburgh).\n\n- `us_states` --- Accepts full state names and two-letter state abbreviations.\n\n- `us_counties_fips` --- Works on string fields that are five-character FIPS county codes for a US county. This layer works only on the interactive map.\n\n- `us_zipcode_tabulation_areas` --- Works on string fields that are five-character US zip codes. Dimensions of [`type: zipcode`](/looker/docs/2512/reference/param-dimension-filter-parameter-types#zipcode) automatically use the `us_zipcode_tabulation_areas` map layer.\n\n \u003e Zip code regions are based on the 2010 zip code tabulation areas (ZCTAs), so this map layer does not include many zip codes, such as those assigned to P.O. boxes, that do not map directly to regions.\n\nExample\n-------\n\n dimension: state {\n map_layer_name: us_states\n sql: ${TABLE}.state ;;\n }"]]