Validators (E-codes)

July 8, 2026 · View on GitHub

Validators check conformance with the MapLibre / Mapbox GL Style Spec. All validator diagnostics use E codes and are emitted by styl validate and styl check.

E001 — Invalid version

Style version must equal 8.

{ "version": 7 }

E002 — Invalid root property value

Out-of-range values on root properties:

Property	Valid range
`center[0]` (longitude)	`-180` to `180`
`center[1]` (latitude)	`-90` to `90`
`zoom`	`0` to `24`
`pitch`	`0` to `85`

bearing is not range-validated (the spec normalizes any value).

E003 — Invalid glyphs URL

glyphs must be a URL template containing both {fontstack} and {range} placeholders.

{ "glyphs": "https://example.com/fonts/{fontstack}/{range}.pbf" }

E004 — Missing source

Non-background, non-sky layers must have a source field (unless they use ref).

Applies to: fill, fill-extrusion, line, symbol, raster, circle, heatmap, hillshade, color-relief.

E005 — Missing source-layer

Layers that reference a vector source must include source-layer.

{
  "sources": { "osm": { "type": "vector", "url": "..." } },
  "layers": [{
    "id": "roads",
    "type": "line",
    "source": "osm"
  }]
}

Fix: add "source-layer": "<layer-name-in-tile>".

E006 — Invalid paint property

A paint property is not valid for the layer's type. See Layer Properties for valid properties per type.

{
  "type": "fill",
  "paint": { "line-width": 2 }
}

E007 — Invalid layout property

A layout property is not valid for the layer's type. See Layer Properties for valid properties per type.

{
  "type": "fill",
  "layout": { "text-field": "hello" }
}

E008 — Invalid sprite

sprite must be a non-empty URL string, or a non-empty array of {id, url} entries where both id and url are non-empty strings.

{ "sprite": "" }
{ "sprite": [] }
{ "sprite": [{"id": "", "url": "https://example.com/sprite"}] }

E009 — Layer source not found

A layer references a source ID that doesn't exist in the top-level sources map.

{
  "sources": {},
  "layers": [{ "id": "roads", "type": "line", "source": "osm" }]
}

E010 — Missing source tiles/url

Vector, raster, and raster-dem sources must have either a url field or a non-empty tiles array.

{ "type": "vector" }

E011 — Invalid source scheme

Source scheme must be "xyz" or "tms". Applies to vector and raster sources.

{ "type": "vector", "url": "...", "scheme": "bad" }

E012 — Invalid raster-dem encoding

raster-dem source encoding must be "terrarium", "mapbox", or "none".

{ "type": "raster-dem", "url": "...", "encoding": "bad" }

E013 — Invalid source zoom range

Source minzoom/maxzoom must be in [0, 22]. minzoom must be ≤ maxzoom. Applies to vector, raster, and raster-dem sources. GeoJSON sources only support maxzoom.

{ "type": "vector", "url": "...", "minzoom": 25 }

E014 — Invalid layer zoom range

Layer minzoom/maxzoom must be in [0, 24]. minzoom must be ≤ maxzoom.

{ "id": "roads", "type": "line", "source": "s", "minzoom": 10, "maxzoom": 5 }

E015 — Invalid source bounds

Source bounds must be [sw_lng, sw_lat, ne_lng, ne_lat] where longitudes are in [-180, 180], latitudes in [-90, 90], and sw ≤ ne. Applies to vector, raster, and raster-dem sources.

{ "type": "vector", "url": "...", "bounds": [-200, -90, 180, 90] }

E016 — Missing GeoJSON data

GeoJSON sources must have a data field set to a GeoJSON object (inline) or a URL string. Absent or null values are not valid.

{ "type": "geojson" }
{ "type": "geojson", "data": null }

Valid forms:

{ "type": "geojson", "data": "https://example.com/data.geojson" }
{ "type": "geojson", "data": { "type": "FeatureCollection", "features": [] } }

E017 — Invalid inline GeoJSON

When data is an inline JSON object, it must be a valid GeoJSON object per RFC 7946 (FeatureCollection, Feature, or Geometry).

{ "type": "geojson", "data": { "type": "NotAGeoJsonType" } }

URL strings are not validated at lint time (remote resource).

E018 — Invalid paint/layout property value

A paint or layout property has a literal value that does not match the MapLibre v8 spec type, range, or enum.

Situation	Example message
Number out of range	`"fill-opacity" expects number in [0, 1], got 1.5`
Number below minimum	`"line-width" expects number >= 0, got -1`
Invalid enum value	`"line-cap" expects one of "butt", "round", or "square", got "flat"`
Invalid color string	`"fill-color" invalid color: "notacolor"`
Wrong type for color	`"fill-color" expects a CSS color string, got number`
Wrong type for boolean	`"fill-antialias" expects boolean, got string`

Expression values (arrays starting with an operator string) are validated structurally via E020–E022 instead.

E019 — Missing layer type

A layer does not have a type field and does not use ref to inherit one from a parent layer.

{ "id": "roads" }

Fix: add "type" with one of: background, fill, fill-extrusion, line, symbol, raster, circle, heatmap, hillshade, sky, color-relief.

Note: color-relief is MapLibre-only. Using it with --spec mapbox or --spec both also triggers E023.

E020 — Empty expression array

An expression must be a non-empty array. [] is not valid.

E021 — Invalid expression argument count

An expression operator received the wrong number of arguments.

"case" requires pairs of [condition, output] plus a final fallback (minimum 4 args, even count)
"match" requires an input, at least one label-output pair, and a fallback (minimum 5 args)
Other operators (e.g. "rgb", "hsl", "at", "slice") enforce their own fixed or minimum arity

["case", true, "red"]

→ E021: "case" requires pairs of [condition, output] plus a fallback

E022 — Unknown expression operator

An expression's first element is not a recognized operator. See Expressions for all supported operators.

E023 — Spec incompatibility

A feature in the style is not supported by the target spec (--spec mapbox or --spec both).

Feature	MapLibre	Mapbox
`sky` layer type	Yes	No
`color-relief` layer type	Yes	No
`terrain` root property	Yes	No
`fog` root property	Yes	No
`distance-from-center` expression	Yes	No
`hsl` expression	No	Yes
`hsla` expression	No	Yes

Example — sky layer with --spec mapbox:

{
  "layers": [{ "id": "s", "type": "sky" }]
}

Fix: remove the incompatible feature, or switch to --spec maplibre if targeting MapLibre only.

E024 — Empty layer id

A layer has an empty string "" for its id. Every layer must have a unique, non-empty id.

{ "id": "", "type": "background" }

E025 — Invalid terrain

The root terrain object has a structural error.

Situation	Example message
Missing `source`	`terrain must have a "source" referencing a raster-dem source`
`source` not a string	`terrain.source must be a string`
`source` ID not in `sources`	`terrain.source "dem" is not defined in sources`
`source` not raster-dem type	`terrain.source "dem" must reference a raster-dem source, got "vector"`
`exaggeration` < 0	`terrain.exaggeration must be >= 0, got -1`
`exaggeration` wrong type	`terrain.exaggeration must be a number`

{ "terrain": { "exaggeration": 1.5 } }

Fix: add "source" referencing an existing raster-dem source id.

E026 — Invalid image/video source coordinates

An image or video source has a coordinate outside valid bounds (longitude in [-180, 180], latitude in [-90, 90]).

{
  "type": "image",
  "url": "...",
  "coordinates": [[-200, 37], [-80, 36], [-79, 36], [-79, 37]]
}

E027 — Invalid light property

The root light object has a property with an invalid value.

Property	Valid values
`anchor`	`"map"` or `"viewport"`
`intensity`	number in `[0, 1]`
`color`	CSS color string
`position`	array of exactly 3 numbers `[radial, azimuthal, polar]`

E028 — Invalid transition property

transition.duration or transition.delay is negative or not a number. Both must be non-negative integers (milliseconds).

{ "transition": { "duration": -100 } }

E029 — Invalid fog property

The root fog object has a property with an invalid value. fog is MapLibre-only; it also triggers E023 under --spec mapbox or --spec both.

Property	Valid values
`color`	CSS color string
`high-color`	CSS color string
`space-color`	CSS color string
`horizon-blend`	number in `[0, 1]`
`star-intensity`	number in `[0, 1]`
`range`	array of exactly 2 numbers `[start, end]` where start ≤ end

{ "fog": { "horizon-blend": 1.5 } }

Expression values (arrays starting with an operator string) are not validated as literals.

E030 — Invalid layer ref

A layer's ref field points to an id that does not exist in the layers array, or points to itself.

{
  "layers": [
    { "id": "derived", "type": "fill", "ref": "missing" }
  ]
}

Fix: set "ref" to the id of an existing layer (not the layer's own id).

E031 — Source type mismatch

A layer type requires a specific source kind, but the referenced source is a different type.

Layer type	Required source type
`raster`	`raster`
`hillshade`	`raster-dem`
`color-relief`	`raster-dem`

{
  "sources": { "roads": { "type": "vector", "url": "..." } },
  "layers": [{ "id": "shading", "type": "hillshade", "source": "roads" }]
}

Fix: change the source to the correct type or change the layer type.

E032 — Image/video source missing content

An image source has an empty url, or a video source has an empty urls array.

{ "type": "image", "url": "", "coordinates": [...] }
{ "type": "video", "urls": [], "coordinates": [...] }

Fix: provide a non-empty URL string for image, or at least one URL in the urls array for video.