Style Reference for Maps SDK for iOS

With style options you can customize the presentation of the standard Google map styles, changing the visual display of features like roads, parks, businesses, and other points of interest. As well as changing the style of these features, you can hide features entirely. This means that you can emphasize particular components of the map or make the map complement the style of the surrounding page.

Examples

The following JSON style declaration turns all map features to gray, then colors arterial road geometry in blue, and hides landscape labels completely:

[
  {
    "featureType": "all",
    "stylers": [
      { "color": "#C0C0C0" }
    ]
  },{
    "featureType": "road.arterial",
    "elementType": "geometry",
    "stylers": [
      { "color": "#CCFFFF" }
    ]
  },{
    "featureType": "landscape",
    "elementType": "labels",
    "stylers": [
      { "visibility": "off" }
    ]
  }
]

The JSON object

A JSON style declaration consists of the following elements:

• featureType (optional) - the features to select for this style modification. Features are geographic characteristics on the map, including roads, parks, bodies of water, and more. If you don't specify a feature, all features are selected.
• elementType (optional) - the property of the specified feature to select. Elements are sub-parts of a feature, including labels and geometry. If you don't specify an element, all elements of the feature are selected.
• stylers - the rules to apply to the selected features and elements. Stylers indicate the color, visibility, and weight of the feature. You can apply one or more stylers to a feature.

To specify a style, you must combine a set of featureType and elementType selectors and your stylers into a style array. You can target any combination of features in a single array. However, the number of styles that you can apply at once is limited. If your style array exceeds the maximum number of characters then no style is applied.

The rest of this page has more information about features, elements and stylers.

featureType

The following JSON snippet selects all roads on the map:

{
  "featureType": "road"
}

Features, or feature types, are geographic characteristics on the map, including roads, parks, bodies of water, businesses, and more.

The features form a category tree, with all as the root. If you don't specify a feature, all features are selected. Specifying a feature of all has the same effect.

Some features contain child features you specify using a dot notation. For example, landscape.natural or road.local. If you specify only the parent feature, such as road, the styles you specify for the parent apply to all its children, such as road.local and road.highway.

Note that parent features may include some elements that are not included in all of their child features.

The following features are available:

• all (default) selects all features.
• administrative selects all administrative areas. Styling affects only the labels of administrative areas, not the geographical borders or fill.
  • administrative.country selects countries.
  • administrative.land_parcel selects land parcels.
  • administrative.locality selects localities.
  • administrative.neighborhood selects neighborhoods.
  • administrative.province selects provinces.
• landscape selects all landscapes.
  • landscape.man_made selects man-made features, such as buildings and other structures.
  • landscape.natural selects natural features, such as mountains, rivers, deserts, and glaciers.
  • landscape.natural.landcover selects land cover features, the physical material that covers the earth's surface, such as forests, grasslands, wetlands, and bare ground.
  • landscape.natural.terrain selects terrain features of a land surface, such as elevation, slope, and orientation.
• poi selects all points of interest.
  • poi.attraction selects tourist attractions.
  • poi.business selects businesses.
  • poi.government selects government buildings.
  • poi.medical selects emergency services, including hospitals, pharmacies, police, doctors, and others.
  • poi.park selects parks.
  • poi.place_of_worship selects places of worship, including churches, temples, mosques, and others.
  • poi.school selects schools.
  • poi.sports_complex selects sports complexes.
• road selects all roads.
  • road.arterial selects arterial roads.
  • road.highway selects highways.
  • road.highway.controlled_access selects highways with controlled access.
  • road.local selects local roads.
• transit selects all transit stations and lines.
  • transit.line selects transit lines.
  • transit.station selects all transit stations.
  • transit.station.airport selects airports.
  • transit.station.bus selects bus stops.
  • transit.station.rail selects rail stations.
• water selects bodies of water.

elementType

The following JSON snippet selects the labels for all local roads:

{
  "featureType": "road.local",
  "elementType": "labels"
}

Elements are subdivisions of a feature. A road, for example, consists of the graphical line (the geometry) on the map, and also the text denoting its name (a label).

The following elements are available, but note that a specific feature may support none, some, or all, of the elements:

• all (default) selects all elements of the specified feature.
• geometry selects all geometric elements of the specified feature.
  • geometry.fill selects only the fill of the feature's geometry.
  • geometry.stroke selects only the stroke of the feature's geometry.
• labels selects the textual labels associated with the specified feature.
  • labels.icon selects only the icon displayed within the feature's label.
  • labels.text selects only the text of the label.
  • labels.text.fill selects only the fill of the label. The fill of a label is typically rendered as a colored outline that surrounds the label text.
  • labels.text.stroke selects only the stroke of the label's text.

stylers

Stylers are formatting options that you can apply to map features and elements.

The following JSON snippet displays a feature as bright green, using an RGB value:

"stylers": [
  { "color": "#99FF33" }
]

This snippet removes all intensity from the color of a feature, regardless of its starting color. The effect is to render the feature grayscale:

"stylers": [
  { "saturation": -100 }
]

This snippet hides a feature completely:

    "stylers": [
      { "visibility": "off" }
    ]

The following style options are supported:

• hue (an RGB hex string of format #RRGGBB) indicates the basic color.

  Note: This option sets the hue while keeping the saturation and lightness specified in the default Google style (or in other style options you define on the map). The resulting color is relative to the style of the base map. If Google makes any changes to the base map style, the changes affect your map's features styled with hue. It's better to use the absolute color styler if you can.

• lightness (a floating point value between -100 and 100) indicates the percentage change in brightness of the element. Negative values increase darkness (where -100 specifies black) while positive values increase brightness (where +100 specifies white).

  Note: This option sets the lightness while keeping the saturation and hue specified in the default Google style (or in other style options you define on the map). The resulting color is relative to the style of the base map. If Google makes any changes to the base map style, the changes affect your map's features styled with lightness. It's better to use the absolute color styler if you can.

• saturation (a floating point value between -100 and 100) indicates the percentage change in intensity of the basic color to apply to the element.

  Note: This option sets the saturation while keeping the hue and lightness specified in the default Google style (or in other style options you define on the map). The resulting color is relative to the style of the base map. If Google makes any changes to the base map style, the changes affect your map's features styled with saturation. It's better to use the absolute color styler if you can.

• gamma (a floating point value between 0.01 and 10.0, where 1.0 applies no correction) indicates the amount of gamma correction to apply to the element. Gamma corrections modify the lightness of colors in a non-linear fashion, while not affecting white or black values. Gamma correction is typically used to modify the contrast of multiple elements. For example, you can modify the gamma to increase or decrease the contrast between the edges and interiors of elements.

  Note: This option adjusts the lightness relative to the default Google style, using a gamma curve. If Google makes any changes to the base map style, the changes affect your map's features styled with gamma. It's better to use the absolute color styler if you can.

• invert_lightness (if true) inverts the existing lightness. This is useful, for example, for quickly switching to a darker map with white text.

  Note: This option simply inverts the default Google style. If Google makes any changes to the base map style, the changes affect your map's features styled with invert_lightness. It's better to use the absolute color styler if you can.

• visibility (on, off, or simplified) indicates whether and how the element appears on the map. A simplified visibility removes some style features from the affected features; roads, for example, are simplified into thinner lines without outlines, while parks lose their label text but retain the label icon.
• color (an RGB hex string of format #RRGGBB) sets the color of the feature.
• weight (an integer value, greater than or equal to zero) sets the weight of the feature, in pixels. Setting the weight to a high value may result in clipping near tile borders.

Style rules are applied in the order that you specify. Do not combine multiple operations into a single style operation. Instead, define each operation as a separate entry in the style array.

Note: Order is important, as some operations are not commutative. Features and/or elements that are modified through style operations (usually) already have existing styles. The operations act on those existing styles, if present.

The hue, saturation, lightness model

Styled maps use the hue, saturation, lightness (HSL) model to denote color within the styler operations. Hue indicates the basic color, saturation indicates the intensity of that color, and lightness indicates the relative amount of white or black in the constituent color.

Gamma correction modifies the lightness over the color space, generally to increase or decrease contrast. Additionally, the HSL model defines color within a coordinate space where hue indicates the orientation within a color wheel, while saturation and lightness indicate amplitudes along different axes. Hues are measured within an RGB color space, which is similar to most RGB color spaces, except that shades of white and black are absent.

While hue takes an HTML hex color value, it only uses this value to determine the basic color - that is, its orientation around the color wheel, not its saturation or lightness, which are indicated separately as percentage changes.

For example, you can define the hue for pure green as hue:0x00ff00 or hue:0x000100. Both hues are identical. Both values point to pure green in the HSL color model.

An RGB Color Wheel

RGB hue values which consist of equal parts red, green and blue do not indicate a hue, because none of those values indicate an orientation in the HSL coordinate space. Examples are "#000000" (black), "#FFFFFF" (white), and all the pure shades of gray. To indicate black, white or gray, you must remove all saturation (set the value to -100) and adjust lightness instead.

Additionally, when modifying existing features which already have a color scheme, changing a value such as hue does not change its existing saturation or lightness.