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AnnotationKeys[obj]

lists all annotation keys available for the object obj.

AnnotationKeys[{obj,itemspec}]

lists all annotation keys available for the items specified by itemspec in obj.

Details
Details and Options Details and Options
Examples  
Basic Examples  
Scope  
Graphs & Networks  
Regions  
Properties & Relations  
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AnnotationKeys

AnnotationKeys[obj]

lists all annotation keys available for the object obj.

AnnotationKeys[{obj,itemspec}]

lists all annotation keys available for the items specified by itemspec in obj.

Details

  • Typically used to extract names in annotations associated to an object and items in an object.
  • AnnotationKeys gives the list of all names keys in key->value annotations for an object and its items.
  • Possible objects with annotations include:
  • Audioaudio with time and duration
    BoundaryMeshRegionboundary mesh with cells
    CSGRegiongeometric regions
    Graphgraph with vertices and edges
    MeshRegionmesh region with cells
  • Item specification itemspec for each object obj is given in its reference page.
  • Option names associated with an object obj are standard annotations for obj except AnnotationRules.

Examples

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Basic Examples  (3)

Get a list of standard annotations in a graph:

Wolfram Language code: g = ExampleData[{"NetworkGraph", "FlorentineFamilies"}]
Wolfram Language code: AnnotationKeys[g]

For a vertex:

Wolfram Language code: AnnotationKeys[{g, "Medici"}]

For an edge:

Wolfram Language code: AnnotationKeys[{g, "Medici""Ridolfi"}]

Test for the presence of MeshCellMarker annotations in cells of dimension 1:

Wolfram Language code: mr = MengerMesh[2, MeshCellMarker -> {{1, 1} -> 1, {1, 2} -> 2, {1, 3} -> 3}]
Wolfram Language code: MemberQ[AnnotationKeys[{mr, 1}], MeshCellMarker]

Get the marker of the cell with index {1,1}:

Wolfram Language code: AnnotationValue[{mr, {1, 1}}, MeshCellMarker]

Automatically compute annotations for an Audio object:

Wolfram Language code: a = AudioAnnotate[Import["ExampleData/rule30.wav"], "Loud"];
Wolfram Language code: AnnotationKeys[a]

Retrieve annotations for louder intervals:

Wolfram Language code: AnnotationValue[a, "Loud"]

Scope  (8)

Graphs & Networks  (6)

AnnotationKeys applies to vertices:

Wolfram Language code: Graph[{Annotation[1, {VertexWeight -> 4, "Material" -> "Wood"}], 2, 3}, {12, 23, 31}]
Wolfram Language code: AnnotationKeys[{%, 1}]

And edges:

Wolfram Language code: Graph[{1, 2, 3}, {Annotation[12, EdgeLabels -> "hello"], 23, 31}]
Wolfram Language code: AnnotationKeys[{%, 12}]

AnnotationKeys works with undirected graphs:

Wolfram Language code: CycleGraph[5, VertexShapeFunction -> "Name"];
Wolfram Language code: AnnotationKeys[{[image], 12}]

Directed graphs:

Wolfram Language code: CycleGraph[5, DirectedEdges -> True, EdgeStyle -> Arrowheads[Small], VertexShapeFunction -> "Name"];
Wolfram Language code: AnnotationKeys[{[image], 12}]

Multigraphs graphs:

Wolfram Language code: Module[{g}, g = Graph[Range[5], {12, 15, 23, 34, 45, 45, 45}, VertexCoordinates -> GraphEmbedding[CycleGraph[5]], VertexShapeFunction -> "Name", PerformanceGoal -> "Quality"]; MapThread[(AnnotationValue[{g, #1}, EdgeStyle] = #2)&, {EdgeList[g], {Gray, Blue, Red, Green, Brown, Brown, Brown}}]; g]
Wolfram Language code: AnnotationKeys[{%, 34}]

Mixed graphs:

Wolfram Language code: Module[{g}, g = Graph[Range[5], {12, 15, 23, 34, 45}, VertexCoordinates -> GraphEmbedding[CycleGraph[5]], VertexShapeFunction -> "Name", PerformanceGoal -> "Quality"]; MapThread[(AnnotationValue[{g, #1}, EdgeStyle] = #2)&, {EdgeList[g], {Gray, Blue, Red, Green, Brown}}]; g]
Wolfram Language code: AnnotationKeys[{%, 15}]

Weighted graphs:

Wolfram Language code: With[{g = CycleGraph[5], w = 0.3Range[5], pl = {Right, Above, Above, Right, Above} /. {Right -> {1 / 2, {-0.4, 1 / 2}}, Above -> {1 / 2, {1 / 2, 0}}}}, Graph[VertexList[g], EdgeList[g], EdgeWeight -> w, VertexShapeFunction -> "Name", EdgeLabels -> Thread[EdgeList[g] -> MapThread[Placed, {w, pl}]], VertexCoordinates -> GraphEmbedding[g]]];
Wolfram Language code: AnnotationKeys[{[image], 12}]

Regions  (2)

AnnotationKeys applies to CSGRegion objects:

Wolfram Language code: CSGRegion["Union", {Ball[], Cuboid[]}]
Wolfram Language code: AnnotationKeys[%]

And their child regions:

Wolfram Language code: CSGRegion["Union", {Ball[], Cuboid[]}]
Wolfram Language code: AnnotationKeys[{%, {1}}]

AnnotationKeys returns both standard and user-defined annotation keys:

Wolfram Language code: CSGRegion["Union", {Annotation[Ball[], "Material" -> "Wood"], Cuboid[]}]
Wolfram Language code: AnnotationKeys[{%, {1}}]

Properties & Relations  (6)

Use Annotation as a wrapper to specify annotations in functions such as Graph:

Wolfram Language code: Graph[{Annotation[1, {VertexSize -> Medium, VertexStyle -> Red}], 2, 3}, {12, 23, 31}]

Use AnnotationValue to extract values:

Wolfram Language code: g = CompleteGraph[4, VertexStyle -> {1 -> Red}, VertexSize -> Small]
Wolfram Language code: AnnotationValue[{g, 1}, VertexStyle]

For undefined annotations, the value $Failed is returned:

Wolfram Language code: AnnotationValue[{g, 1}, "foo"]
Wolfram Language code: MemberQ[AnnotationKeys[{g, 1}], "foo"]

Use AnnotationValue to set annotations in a graph:

Wolfram Language code: g = CompleteGraph[4]
Wolfram Language code: AnnotationValue[{g, 1}, VertexSize] = Small;

The original graph has changed:

Wolfram Language code: g

Use AnnotationValue to unset annotations in a graph:

Wolfram Language code: g = CompleteGraph[4, VertexSize -> {1 -> Small}]
Wolfram Language code: AnnotationValue[{g, 1}, VertexSize]=.;

The original graph has changed:

Wolfram Language code: g

Use Annotate to set the annotations in a new graph:

Wolfram Language code: g = CompleteGraph[4]
Wolfram Language code: Annotate[{g, 1}, VertexSize -> Small]

The original graph is unchanged:

Wolfram Language code: g

Use AnnotationDelete to remove an annotation without changing the original:

Wolfram Language code: g = CompleteGraph[4, VertexSize -> {1 -> Small}]
Wolfram Language code: AnnotationDelete[{g, 1}, VertexSize]

The original graph is unchanged:

Wolfram Language code: g
Wolfram Research (2020), AnnotationKeys, Wolfram Language function, https://reference.wolfram.com/language/ref/AnnotationKeys.html (updated 2025).

Text

Wolfram Research (2020), AnnotationKeys, Wolfram Language function, https://reference.wolfram.com/language/ref/AnnotationKeys.html (updated 2025).

CMS

Wolfram Language. 2020. "AnnotationKeys." Wolfram Language & System Documentation Center. Wolfram Research. Last Modified 2025. https://reference.wolfram.com/language/ref/AnnotationKeys.html.

APA

Wolfram Language. (2020). AnnotationKeys. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/AnnotationKeys.html

BibTeX

@misc{reference.wolfram_2026_annotationkeys, author="Wolfram Research", title="{AnnotationKeys}", year="2025", howpublished="\url{https://reference.wolfram.com/language/ref/AnnotationKeys.html}", note=[Accessed: 12-June-2026]}

BibLaTeX

@online{reference.wolfram_2026_annotationkeys, organization={Wolfram Research}, title={AnnotationKeys}, year={2025}, url={https://reference.wolfram.com/language/ref/AnnotationKeys.html}, note=[Accessed: 12-June-2026]}