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If using Windows, we recommend using 7-Zip to unzip the exported labels.

Label Coordinates

In the JSON format, label coordinates are normalized to be between 0 and 1. This means that the corners of the frame or image correspond to the coordinates (1,1), (1,0), (0,0), (0,1) regardless of frame dimensions. To get the pixel values of normalized coordinates:
  • The x and h coordinates of a label should be multiplied by the pixel width of the frame or image.
  • The y and w coordinates of a label should be multiplied by the pixel height of the frame or image.

Format of Exported Labels

The last_edited_by and last_edited_at fields are updated only when the label or its nested attributes are modified in the Label Editor. If the SDK is used to update the label, these fields must be updated manually.
The tables below provide descriptions of all values contained JSON format exports.
Exports of label versions for which the data unit was deleted vary from the examples shown below - the data_type is deleted, while image groups and image sequences only contain a single data_unit.
Exported labels include several unique identifiers that nest. The root of each label starts with the object_hash for the Ontology object or classification.
Exported Label Structure

Single Images

The export contains a list of JSON objects, with each JSON object representing a single data unit and containing detailed information for all exported labels. The example below describes all the keys for a single exported data unit.
[
    {
        "classification_answers": {},
        "created_at": "2025-01-07 16:12:23",
        "data_hash": "f3132c00-069f-4a95-8e21-30c13078d84d",
        "data_title": "Image3.jpg",
        "data_type": "image",
        "data_units": {
        },
        "dataset_hash": "3c35b0f2-64fc-4a58-9b9d-f7181d73f1e5",
        "dataset_title": "New Welsh Whales",
        "is_image_sequence": null,
        "is_valid": true,
        "label_hash": "0f5a5e62-a3e0-4481-932f-1093f7c1d170",
        "label_status": "LABEL_IN_PROGRESS",
        "last_edited_at": "2025-01-07 16:12:23",
        "object_actions": {},
        "object_answers": {},
        "video_link": null
    }
]
KeyDescriptionNotes
label_hashThe Label Row hashThe ‘hash’ represents a unique identifier
created_atTime and date the label was created
last_edited_atTime and date the label was last edited
dataset_hashThe Dataset’s hashThe ‘hash’ represents a unique identifier
data_typeThe data unit’s file formatAlways “video” for videos
is_image_sequence”true” when the data unit is an image sequenceAlways “null” for images
video_linkContains a private cloud URL for videosAlways “null” for images
data_unitsList of all files the data unit is composed ofDetails of the export information for `data_units“ can be found below.
object_answersAll the attributes in this data unitThe object attributes are identified using their hash
classification_answersAll the classifications in a particular data unitThe classification labels are identified using their hash
object_actionsThe number of states a dynamic attribute can be in.A change in state occurs each time the attribute answer changes. The objectHash within the object_actions is the attribute answer’s ID.
label_statusIndicates whether the data unit has been labeled.
export_historyContains a record of the export history for this data unitExporting labels to confirm export history generates an export history entry.
export_hashThe hash for this particular export instanceThe ‘hash’ represents a unique identifier
exported_atThe date and time when a particular export instance took place.
The data_units key contains all files that compose the data unit. For a given image there is only ever a single element in this list. This element contains the following information.
data_units here refer to individual files that compose a data unit, as defined in our glossary, and are not to be confused with data units elsewhere in the platform. Encord will update this nomenclature soon, but we always communicate changes to all customers first.

"data_units": {
      "9c588f63-ad87-4987-a074-06ba0d6980cd": {
        "data_hash": "9c588f63-ad87-4987-a074-06ba0d6980cd",
        "data_title": "dom-hbf.jpg",
        "data_type": "image",
        "data_sequence": 0,
        "labels": { },
        "data_fps": "23.976023976023978" ,
        "data_duration": "29.0786",
        "data_link": "www.my-private-cloud.com/how-to-make-apple-pie.mp4",
        "width": 512,
        "height": 512
      }
}  
KeyDescriptionNotes
data_hashThe file’s hashThe ‘hash’ represents a unique identifier
data_titleThe file’s title
data_typeThe file type
data_sequenceThe sequence number of this file within the data unitAlways 0 for images, as single images are composed of a single file by definition
labelsA container for the image’s label informationThis contains the label information for the image.
data_linkA link to the file stored in your private cloud
widthThe width of the image in pixel (px)
heightThe height of the image in pixel (px)
labels contains all object labels, classification labels, and attributes present in the image.

"labels": {
      "0": {
        "objects": { },
        "classifications": [ ]
      }
}  
KeyDescriptionNotes
objectsA list of label objects in this frameContains geometric information for object labels
classificationsA list of classifications applying to image as a whole
objects contains all object label information for the image. A key with the name of the object shape is always present - bounding_box in the example below. All shapes contain coordinates for each vertex.
Navigate to the ontology shapes section to see how all ontology classes are represented in the exported file.
The example below shows a single object instance.
{
"objects": [
{
"featureHash": "Aav9W+cC",
"objectHash": "cTkqn7d7",
"name": "Cherries",
"value": "cherries",
"color": "#595feb",
"shape": "bounding_box",
"confidence": 1,
"frame": 0,
"createdBy": "chris-encord@acme.com",
"createdAt": "Wed, 28 May 2025 08:51:53 GMT",
"lastEditedBy": "chris-encord@acme.com",
"lastEditedAt": "Wed, 28 May 2025 08:51:53 GMT",
"manualAnnotation": true,
"boundingBox": {
  "x": 0.34688227662041876,
  "y": 0.4167629800853485,
  "w": 0.29148041861853874,
  "h": 0.41461619320558957
}
}
]
}

KeyDescriptionNotes
objectHashThe specific label’s hashThe ‘hash’ represents a unique identifier
featureHashThe Ontology object’s hashCorresponds to the FeatureNodeHash in the ontology
nameThe object’s nameAs specified in the ontology
valueThe name given to the object
colorThe color used to draw the objectAs specified in the ontology
shapeThe Ontology class used to create the objectAs specified in the ontology
confidenceThe confidence score for this objectA confidence score of 1 is given for all labels created manually. More info can be found here
frameThe frame number of the data unit where the label appearsA frame number of 0 represents the first frame of the data unit. Images always have a frame number of 0.
createdByThe email of the user that created this object
createdAtDate and time the object was created
lastEditedByThe email of the user that last edited this object
lastEditedAtDate and time the object was last edited
manualAnnotationA field indicating whether the object was drawn manually or nottrue means it was drawn manually, while false means it was created using a model or an automated labeling technique
boundingBoxA list containing the coordinates for the bounding boxRefer to the ontology shapes section for more details
classifications contains all classification information for the image.The following example shows a single object instance.
"classifications": [
  {
        "name": "Time of day",
        "value": "time_of_day",
        "createdAt":"Tue, 10 Oct 2023 14:16:14 GMT",
        "createdBy": "david.babuschkin@encord.com",
        "confidence": "1",
        "featureHash": "wUS7p9B6",
        "lastEditedAt": "Tue, 10 Oct 2023 14:16:14 GMT",
        "classificationHash": "jiOiEq76",
        "manualAnnotation": true
      }
]  
KeyDescriptionNotes
nameThe classification’s nameAs specified in the ontology
valueThe classification valueSame as the name
createdAtTime and day the classification was created
createdByThe email of the user that created this classification
confidenceThe confidence score for this classificationA confidence score of 1 is given for all labels created manually. More info can be found here
featureHashThe classification instance hashCorresponds to the FeatureNodeHash in the Ontology
lastEditedAtTime and date of the last time this classification was edited
classificationHashThe classification instance hash hash
manualAnnotationA field indicating whether the object was drawn manually or nottrue means it was drawn manually, while false means it was created using a model or an automated labeling technique
object_answers is a list of objects that have at least one nested attribute and contains information for all attributes. Expanding object_answers reveals the following:
"object_answers": {
  "Gqh06ypx"
      "objectHash": "Gqh06ypx",
      "classifications" [ 
        "name": "Size",
        "value": "size",
        "answers": "Medium",
        "featureHash": "GZnFumFq",
        "manualAnnotation": true
      ]
}  
KeyDescriptionNotes
objectHashThe hash of the object containing the attributesThe ‘hash’ represents a unique identifier
classificationsA list of attributes related to the object. Includes Dynamic attributes and Relation attributesNot to be confused with classifications as defined in our glossary, which apply to a frame
nameThe attribute name
valueThe attribute valueAlways the same as the name
answersThe value(s) the attribute(s) were set toIf the attribute was a radio button, the answer is the option selected by the annotator
featureHashThe attribute’s hashThe ‘hash’ represents a unique identifier
manualAnnotationA field indicating whether the object was drawn manually or nottrue means it was drawn manually, while false means it was created using a model or an automated labeling technique
Contains a list of classifications that apply to entire frames or slices. classification_answer is represented by its hash. Expanding classification_answers reveals the following:
"classification_answers": {
  "OFX2jzwE": {
    "classificationHash": "OFX2jzwE", 
    "classifications": [{
      "name": "Time of day", 
      "value": "time_of_day", 
      "answers": [{
        "name": "Night", 
        "value": "night", 
        "featureHash": "j/7dpSmi"}],    
    "featureHash": "uZmB5YZC", 
    "manualAnnotation": true
    }]
  }
}
KeyDescriptionNotes
classificationHashThe classification’s hashCorresponds to the featureNodeHash in the Ontology
classificationsA list of classification information
nameThe classification nameAs set in the Ontology (Quality in the example above)
valueThe classification valueAlways the same as the classification name
answersA list of all classification answers”answers” refer to the values the classification were set to.
nameThe name of the classification answer”Night” in the example above
valueThe classification answer’s valueAlways the same as the classifications answer’s name
featureHashThe hash for the particular classification answerIncluded in answers
featureHashThe hash for the particular classification
manualAnnotation”true” for all manually created labels. “false” for all labels created with automated labeling techniques
The export_history contains a list of all exports for this data unit, the first entry being the current export. Each instance contains the following:
"export_history": {
  "0"
      "export_hash": "Gqh06ypx",
      "exported_at": "Mon, 02 Oct 2023 13:47:45 UTC",
      "user_email": "david.babuschkin@encord.com"
}  
KeyDescriptionNotes
export_hashThe export instance’s hashThe ‘hash’ represents a unique identifier
exported_atDate and time of the export
user_emailThe email of the user that made this export

Image Groups & Image Sequences

Confused about the difference between image groups and image sequences? See our documentation here to learn about different data types in Encord.
The export contains a list of JSON objects, with each JSON object representing a single image group or image sequence, and containing detailed information for all exported labels. The example below describes all the keys for a single exported data unit.
[
  {
    "label_hash": "781dd0ff-e4c2-48f1-bcd1-09f2f0756701",
    "created_at": "2023-03-23 11:42:14",
    "last_edited_at": "2023-10-02 13:53:03",
    "dataset_hash": "4a4141ed-8d8b-4518-b1f7-97a5c53e992b",
    "dataset_title": "cooking_image_sequences",
    "data_title": "image-group-67bdc95d",
    "data_hash": "9c588f63-ad87-4987-a074-06ba0d6980cd",
    "data_type": "image_group",
    "is_image_sequence": null,
    "image_sequence_link": "www.my-private-cloud.com/how-to-make-apple-pie.mp4",
    "data_units": { },
    "classification_answers": { },
    "object_actions": { },
    "label_status": "LABELLED",
    "export_history": [
      {
        "export_hash": "02b56519-9664-4e38-9713-4817a5caf648",
        "exported_at": "Mon, 02 Oct 2023 14:35:30 UTC",
        "user_email": "david.babuschkin@encord.com"
      },
      {
        "export_hash": "2e0ee531-41ce-4ce9-a859-b6b47697e5d2",
        "exported_at": "Mon, 02 Oct 2023 13:47:45 UTC",
        "user_email": "david.babuschkin@encord.com"
      }
    ],
    "export_hash": "02b56519-9664-4e38-9713-4817a5caf648",
    "exported_at": "Mon, 02 Oct 2023 14:35:30 UTC",
  }
]
KeyDescriptionNotes
label_hashThe Label Row hashThe ‘hash’ represents a unique identifier
created_atTime and date the label was created
last_edited_atTime and date the label was last edited
dataset_hashThe dataset’s hashThe ‘hash’ represents a unique identifier
data_typeThe data unit’s file formatAlways “img_group” for image groups and image sequences
is_image_sequencetrue when the data unit is an image sequencefalse for all other types of data, including image groups. This is what distinguishes image groups and image sequences in your export
video_linkContains a link to file storage location if file is a videoAlways “null” for image groups and image sequences
data_unitsList of all files the data unit is composed ofDetails of the export information for data units can be found below.
object_answersAll the attributes in this data unitThe object attributes are identified using their hash
classification_answersAll the classifications in a particular data unitThe classification labels are identified using their hash
object_actionsThe number of states a dynamic attribute can be in.A change in state occurs each time the attribute answer changes. The objectHash within the object_actions is the attribute answer’s ID.
label_statusIndicates whether the data unit has been labeled.
export_historyContains a record of the export history for this data unitExporting labels to confirm export history generates an export history entry.
export_hashThe hash for this particular export instanceThe ‘hash’ represents a unique identifier
exported_atThe date and time when a particular export instance took place.

The data_units key contains a list of all files that compose the image group or image sequence (sometimes referred to as frames). It contains the following information.
data_units here refer to individual files that compose a data unit, as defined in our glossary, and are not to be confused with data units elsewhere in the platform. Encord will update this nomenclature soon, but we always communicate changes to all customers first.

"data_units": {
      "9c588f63-ad87-4987-a074-06ba0d6980cd": {
        "data_hash": "9c588f63-ad87-4987-a074-06ba0d6980cd",
        "data_title": "rhein-hafen.jpg4",
        "data_type": "image/jpg",
        "data_sequence": 0,
        "labels": { },
        "data_link": "www.my-private-cloud.com/how-to-make-apple-pie.mp4",
        "width": 512,
        "height": 512
      }
}  
KeyDescriptionNotes
data_hashThe file’s hashThe ‘hash’ represents a unique identifier
data_titleThe file’s title
data_typeThe file type
data_sequenceThe sequence number of this file within the data unit0 represents the first file
labelsA list of all frames contained in image group or sequence, and any labels on each frameThis contains the label information for each frame.
widthThe width of the frame in pixel (px)
heightThe height of the frame in pixel (px)
Each number within labels represents an individual frame within the image group or sequence. Each frame contains the following:

"labels": {
      "0": {
        "objects": { },
        "classifications": [ ],
        "metadata":{ }
      }
}  
KeyDescriptionNotes
objectsA list of label objects in this frameContains geometric information for object labels
classificationsA list of classifications applying to the entire frameIs the same value for all instances of this classification.
objects contains label information for all object instances in a frame. A key with the name of the object shape is always present - bounding_box in the example below. All shapes contain coordinates for each vertex.
Navigate to the ontology shapes section to see how all ontology classes are represented in the exported file.
The example below shows a single object instance.
"objects": [
      {
        "name": "Apple",
        "color": "#D33115",
        "shape":"bounding_box",
        "value": "apple",
        "boundingBox": {
          "0": {
            "h": 0.3235,
            "w": 0.1697,
            "x": 0.0153,
            "y": 0.254,   
          }
        },
        "createdAt": "Thu, 07 Sep 2023 09:47:35 GMT",
        "createdBy": "david.babuschkin@encord.com",
        "confidence": "1",
        "objectHash": "P6gqJT/3",
        "featureHash": "jiOiEq76",
        "manualAnnotation": true
      }
]  
KeyDescriptionNotes
nameThe object’s nameAs specified in the ontology
colorThe color used to draw the objectAs specified in the ontology
shapeThe Ontology class used to create the objectAs specified in the ontology
valueThe name given to the object
createdAtDate and time the object was created
createdByThe email of the user that created this object
confidenceThe confidence score for this objectA confidence score of 1 is given for all labels created manually. More info can be found here
objectHashThe specific label’s hashThe ‘hash’ represents a unique identifier
featureHashThe Ontology object’s hashCorresponds to the FeatureNodeHash in the ontology
manualAnnotationA field indicating whether the object was drawn manually or nottrue means it was drawn manually, while false means it was created using a model or an automated labeling technique
boundingBoxA list containing the coordinates for the bounding boxRefer to the ontology shapes section for more details
classifications contains all frame level classification information for the image group or sequence.The example below shows a single classification instance.
"classifications": [
      {
        "name": "Time of day",
        "value": "time_of_day",
        "createdAt":"Tue, 10 Oct 2023 14:16:14 GMT",
        "createdBy": "david.babuschkin@encord.com",
        "confidence": "1",
        "featureHash": "wUS7p9B6",
        "lastEditedAt": "Tue, 10 Oct 2023 14:16:14 GMT",
        "classificationHash": "jiOiEq76",
        "manualAnnotation": true
      }
]  
KeyDescriptionNotes
nameThe classification’s nameAs specified in the ontology
valueThe classification valueSame as the name
createdAtTime and day the classification was created
createdByThe email of the user that created this classification
confidenceThe confidence score for this classificationA confidence score of 1 is given for all labels created manually. More info can be found here
featureHashThe classification instance hashCorresponds to the FeatureNodeHash in the Ontology
lastEditedAtTime and date of the last time this classification was edited
classificationHashThe classification instance hash hash
manualAnnotationA field indicating whether the object was drawn manually or nottrue means it was drawn manually, while false means it was created using a model or an automated labeling technique
object_answers is a list of objects that have at least one nested attribute and contains information for all attributes. Expanding object_answers reveals the following:
"object_answers": {
  "Gqh06ypx"
      "objectHash": "Gqh06ypx",
      "classifications" [{ 
        "name": "Size",
        "value": "size",
        "answers": "Medium",
        "featureHash": "GZnFumFq",
        "manualAnnotation": true
  }]
}  
KeyDescriptionNotes
objectHashThe hash of the object containing the attributesThe ‘hash’ represents a unique identifier
classificationsA list of attributes related to the object. Includes Dynamic attributes and Relation attributesNot to be confused with classifications as defined in our glossary, which apply to a frame
nameThe attribute name
valueThe attribute valueAlways the same as the name
answersThe value(s) the attribute(s) were set toIf the attribute was a radio button, the answer is the option selected by the annotator
featureHashThe attribute’s hashThe ‘hash’ represents a unique identifier
manualAnnotationA field indicating whether the object was drawn manually or nottrue means it was drawn manually, while false means it was created using a model or an automated labeling technique
Contains a list of classifications that apply to entire frames or slices. classification_answer is represented by its hash. Expanding classification_answers reveals the following:
"classification_answers": {
  "OFX2jzwE": {
    "classificationHash": "OFX2jzwE", 
    "classifications": [{
      "name": "Quality", 
      "value": "quality", 
      "answers": [{
        "name": "out of focus", 
        "value": "out_of_focus", 
        "featureHash": "j/7dpSmi"}],    
    "featureHash": "uZmB5YZC", 
    "manualAnnotation": true
    }]
  }
}
KeyDescriptionNotes
classificationHashThe classification’s hashThe ‘hash’ represents a unique identifier
classificationsA list of classifications information
nameThe classification nameAs set in the Ontology (Quality in the example above)
valueThe classification valueAlways the same as the classification name
answersA list of all classification answers”answers” refer to the values the classifications were set to.
nameThe name of the classification answer”out of focus” in the example above
valueThe classification answer’s valueAlways the same as the classification answer’s name
featureHashThe hash for the particular classification answerIncluded in answers
featureHashThe hash for the particular classification
manualAnnotation”true” for all manually created labels. “false” for all labels created with automated labeling techniques
The export_history contains a list of all exports for this data unit, the first entry being the current export. Each instance contains the following:
"export_history": {
  "0"
      "export_hash": "Gqh06ypx",
      "exported_at": "Mon, 02 Oct 2023 13:47:45 UTC",
      "user_email": "david.babuschkin@encord.com"
}  
KeyDescriptionNotes
export_hashThe export instance’s hashThe ‘hash’ represents a unique identifier
exported_atDate and time of the export
user_emailThe email of the user that made this export

Videos

The export contains a list of JSON objects, with each JSON object representing a single data unit and containing detailed information for all exported labels. The example below describes all the keys for a single exported data unit.

[
  {
    "label_hash": "781dd0ff-e4c2-48f1-bcd1-09f2f0756701",
    "created_at": "2023-03-23 11:42:14",
    "last_edited_at": "2023-10-02 13:53:03",
    "dataset_hash": "4a4141ed-8d8b-4518-b1f7-97a5c53e992b",
    "dataset_title": "cooking_videos",
    "data_title": "how-to-make-apple-pie.mp4",
    "data_hash": "9c588f63-ad87-4987-a074-06ba0d6980cd",
    "data_type": "video",
    "is_image_sequence": null,
    "video_link": "www.my-private-cloud.com/how-to-make-apple-pie.mp4",
    "data_units": { },
    "classification_answers": { },
    "object_actions": { },
    "label_status": "LABELLED",
    "export_history": [
      {
        "export_hash": "02b56519-9664-4e38-9713-4817a5caf648",
        "exported_at": "Mon, 02 Oct 2023 14:35:30 UTC",
        "user_email": "david.babuschkin@encord.com"
      },
      {
        "export_hash": "2e0ee531-41ce-4ce9-a859-b6b47697e5d2",
        "exported_at": "Mon, 02 Oct 2023 13:47:45 UTC",
        "user_email": "david.babuschkin@encord.com"
      }
    ],
    "export_hash": "02b56519-9664-4e38-9713-4817a5caf648",
    "exported_at": "Mon, 02 Oct 2023 14:35:30 UTC",
  }
]

KeyDescriptionNotes
label_hashThe Label Row hashThe ‘hash’ represents a unique identifier
created_atTime and date the label was created
last_edited_atTime and date the label was last edited
dataset_hashThe Dataset’s hashThe ‘hash’ represents a unique identifier
data_typeThe data unit’s file formatAlways “video” for videos
is_image_sequence”true” when the data unit is an image sequenceAlways “null” for videos
video_linkLink to the video saved on your private cloudAlways “null” for all other file types
data_unitsList of all files the data unit is composed ofDetails of the export information for `data_units“ can be found below.
object_answersAll the attributes in this data unitThe object attributes are identified using their hash
classification_answersAll the classifications in a particular data unitThe classification labels are identified using their hash
object_actionsThe number of states a dynamic attribute can be in.A change in state occurs each time the attribute answer changes. The objectHash within the object_actions is the attribute answer’s ID.
label_statusIndicates whether the data unit has been labeled.
export_historyContains a record of the export history for this data unitExporting labels to confirm export history generates an export history entry.
export_hashThe hash for this particular export instanceThe ‘hash’ represents a unique identifier
exported_atThe date and time when a particular export instance took place.

The data_units key contains all files that compose the data unit. For a given video there is only a single element in this list. This element contains the following information.
data_units here refer to individual files that compose a data unit, as defined in our glossary, and are not to be confused with data unit elsewhere in the platform. Encord will update this nomenclature soon, but we always communicate changes to all customers first.

"data_units": {
      "9c588f63-ad87-4987-a074-06ba0d6980cd": {
        "data_hash": "9c588f63-ad87-4987-a074-06ba0d6980cd",
        "data_title": "how-to-make-apple-pie.mp4",
        "data_type": "video/mp4",
        "data_sequence": 0,
        "labels": { },
        "data_fps": "23.976023976023978" ,
        "data_duration": "29.0786",
        "data_link": "www.my-private-cloud.com/how-to-make-apple-pie.mp4",
        "width": 512,
        "height": 512
      }
}  
KeyDescriptionNotes
data_hashThe file’s hashThe ‘hash’ represents a unique identifier
data_titleThe file’s title
data_typeThe file type
data_sequenceThe sequence number of this file within the data unit0 represents the first file
labelsA list of all frames contained in the video and any labels on each frameThis contains the label information for each frame.
data_fpsThe frames per second for this video
data_durationThe video lengthIn seconds
data_linkA link to the file stored in your private cloud
widthThe width of the frame in pixel (px)
heightThe height of the frame in pixel (px)
Each number within labels represents an individual frame within the data unit. Each frame contains the following:

"labels": {
      "0": {
        "objects": { },
        "classifications": [ ],
        "metadata":{ }
      }
}  
KeyDescriptionNotes
objectsA list of label objects in this frameContains geometric information for object labels
classificationsA list of classifications applying to the entire frameIs the same value for all instances of this classification.
objects contains label information for all object instances in a frame. A key with the name of the object shape is always present - bounding_box in the example below. All shapes contain coordinates for each vertex.
Navigate to the ontology shapes section to see how all ontology classes are represented in the exported file.
The following example shows a single object instance.
"objects": [
  {
        "name": "Apple",
        "color": "#D33115",
        "shape":"bounding_box",
        "value": "apple",
        "boundingBox": {
          "0": {
            "h": 0.3235,
            "w": 0.1697,
            "x": 0.0153,
            "y": 0.254,   
          }
        },
        "createdAt": "Thu, 07 Sep 2023 09:47:35 GMT",
        "createdBy": "david.babuschkin@encord.com",
        "confidence": "1",
        "objectHash": "P6gqJT/3",
        "featureHash": "jiOiEq76",
        "manualAnnotation": true
      }
]  
KeyDescriptionNotes
nameThe object’s nameAs specified in the ontology
colorThe color used to draw the objectAs specified in the ontology
shapeThe ontology class used to create the objectAs specified in the ontology
valueThe name given to the object
createdAtDate and time the object was created
createdByThe email of the user that created this object
confidenceThe confidence score for this objectA confidence score of 1 is given for all labels created manually. More info can be found here
objectHashThe specific label’s hashThe ‘hash’ represents a unique identifier
featureHashThe Ontology object’s hashCorresponds to the FeatureNodeHash in the ontology
manualAnnotationA field indicating whether the object was drawn manually or nottrue means it was drawn manually, while false means it was created using a model or an automated labeling technique
boundingBoxA list containing the coordinates for the bounding boxRefer to the ontology shapes section for more details
classifications contains all frame level classification information for the video.The example below shows a single classification instance.
"classifications": [
  {
        "name": "Time of day",
        "value": "time_of_day",
        "createdAt":"Tue, 10 Oct 2023 14:16:14 GMT",
        "createdBy": "david.babuschkin@encord.com",
        "confidence": "1",
        "featureHash": "wUS7p9B6",
        "lastEditedAt": "Tue, 10 Oct 2023 14:16:14 GMT",
        "classificationHash": "jiOiEq76",
        "manualAnnotation": true
      }
]  
KeyDescriptionNotes
nameThe classification’s nameAs specified in the ontology
valueThe classification valueSame as the name
createdAtTime and day the classification was created
createdByThe email of the user that created this classification
confidenceThe confidence score for this classificationA confidence score of 1 is given for all labels created manually. More info can be found here
featureHashThe classification instance hashCorresponds to the FeatureNodeHash in the Ontology
lastEditedAtTime and date of the last time this classification was edited
classificationHashThe classification instance hash hash
manualAnnotationA field indicating whether the object was drawn manually or nottrue means it was drawn manually, while false means it was created using a model or an automated labeling technique
object_answers is a list of objects that have at least one nested attribute and contains information for all attributes. Expanding object_answers reveals the following:
"object_answers": {
  "Gqh06ypx"
      "objectHash": "Gqh06ypx",
      "classifications" [ 
        "name": "Size",
        "value": "size",
        "answers": "Medium",
        "featureHash": "GZnFumFq",
        "manualAnnotation": true
      ]
}  
KeyDescriptionNotes
objectHashThe hash of the object containing the attributesThe ‘hash’ represents a unique identifier
classificationsA list of attributes related to the objectNot to be confused with classifications as defined in our glossary, which apply to a frame
nameThe attribute name
valueThe attribute valueAlways the same as the name
answersThe value(s) the attribute(s) were set toIf the attribute was a radio button, the answer is the option selected by the annotator
featureHashThe attribute’s hashThe ‘hash’ represents a unique identifier
manualAnnotationA field indicating whether the object was drawn manually or nottrue means it was drawn manually, while false means it was created using a model or an automated labeling technique
Contains a list of classifications that apply to entire frames or slices. classification_answer is represented by its hash. Expanding classification_answers reveals the following:
"classification_answers": {
  "OFX2jzwE": {
    "classificationHash": "OFX2jzwE", 
    "classifications": [{
      "name": "Quality", 
      "value": "quality", 
      "answers": [{
        "name": "out of focus", 
        "value": "out_of_focus", 
        "featureHash": "j/7dpSmi"}],    
    "featureHash": "uZmB5YZC", 
    "manualAnnotation": true
    }]
  }
}
KeyDescriptionNotes
classificationHashThe classification’s hashThe ‘hash’ represents a unique identifier
classificationsA list of classifications information
nameThe classification nameAs set in the ontology (Quality in the example above)
valueThe classification valueAlways the same as the classification name
answersA list of all classification answers”answers” refer to the values the classifications were set to.
nameThe name of the classification answer”out of focus” in the example above
valueThe classification answer’s valueAlways the same as the classification answer’s name
featureHashThe hash for the particular classification answerIncluded in answers
featureHashThe hash for the particular classification
manualAnnotation”true” for all manually created labels. “false” for all labels created with automated labeling techniques
The export_history contains a list of all exports for this data unit, the first entry being the current export. Each instance contains the following:
"export_history": {
  "0"
      "export_hash": "Gqh06ypx",
      "exported_at": "Mon, 02 Oct 2023 13:47:45 UTC",
      "user_email": "david.babuschkin@encord.com"
}  
KeyDescriptionNotes
export_hashThe export instance’s hashThe ‘hash’ represents a unique identifier
exported_atDate and time of the export
user_emailThe email of the user that made this export

DICOM

The export contains a list of JSON objects, with each JSON object representing a single data unit and containing detailed information for all exported labels. The following example describes all the keys for a single exported data unit.

[
  {
    "label_hash": "781dd0ff-e4c2-48f1-bcd1-09f2f0756701",
    "created_at": "2023-03-23 11:42:14",
    "last_edited_at": "2023-10-02 13:53:03",
    "dataset_hash": "4a4141ed-8d8b-4518-b1f7-97a5c53e992b",
    "dataset_title": "BB: CT thin slices",
    "data_title": "9c58",
    "data_hash": "9c588f63-ad87-4987-a074-06ba0d6980cd",
    "data_type": "dicom",
    "is_image_sequence": null,
    "video_link": null,
    "data_units": { },
    "classification_answers": { },
    "object_actions": { },
    "label_status": "LABELLED",
    "export_history": [
      {
        "export_hash": "02b56519-9664-4e38-9713-4817a5caf648",
        "exported_at": "Mon, 02 Oct 2023 14:35:30 UTC",
        "user_email": "david.babuschkin@encord.com"
      },
      {
        "export_hash": "2e0ee531-41ce-4ce9-a859-b6b47697e5d2",
        "exported_at": "Mon, 02 Oct 2023 13:47:45 UTC",
        "user_email": "david.babuschkin@encord.com"
      }
    ],
    "export_hash": "02b56519-9664-4e38-9713-4817a5caf648",
    "exported_at": "Mon, 02 Oct 2023 14:35:30 UTC",
  }
]

KeyDescriptionNotes
label_hashThe Label Row hashThe ‘hash’ represents a unique identifier
created_atTime and date the label was created
last_edited_atTime and date the label was last edited
dataset_hashThe dataset’s hashThe ‘hash’ represents a unique identifier
data_typeThe data unit’s file formatAlways “dicom” in a DICOM series
is_image_sequence”true” when the data unit is an image sequenceAlways “null” for a DICOM series
video_linkLink to the video or image sequenceAlways “null” for a DICOM series
data_unitsList of all files the data unit is composed ofDetails of the export information for `data_units“ can be found below.
object_answersAll the object attributes in this data unitThe object attribute are identified using their hash
classification_answersAll the classifications in a particular data unitThe classification labels are identified using their hash
object_actionsThe number of states a dynamic attribute can be in.A change in state occurs each time the attribute answer changes. The objectHash within the object_actions is the attribute answer’s ID.
label_statusIndicates whether the data unit has been labeled.
export_historyContains a record of the export history for the data unitExporting labels to confirm export history generates an export history entry.
export_hashThe hash for this particular export instanceThe ‘hash’ represents a unique identifier
exported_atThe date and time when a particular export instance took place.

The data_units key contains all files that compose the data unit.
data_units here refer to individual files that compose a data unit, as defined in our glossary, and are not to be confused with data units elsewhere in the platform. Encord will update this nomenclature soon, but we always communicate changes to all customers first.

"data_units": {
      "9c588f63-ad87-4987-a074-06ba0d6980cd": {
        "data_hash": "9c588f63-ad87-4987-a074-06ba0d6980cd",
        "data_title": "9c58",
        "data_type": "application/dicom",
        "data_sequence": 0,
        "labels": { },
        "metadata": {  },
        "data_links": { },
        "width": 512,
        "height": 512
      }
}  
KeyDescriptionNotes
data_hashThe file’s hashThe ‘hash’ represents a unique identifier
data_titleThe file’s title
data_typeThe file type
data_sequenceThe sequence number of this file within the data unit0 represents the first file
labelsA list of all slices contained in the series and any labels on each sliceThis contains the label information for each slice.
metadataThe DICOM series metadata.Contains the ID for the patient, the study, and the series.
data_linksLinks to all slices within the series, ordered by their sequence number
widthThe width of the slice in pixel (px)
heightThe height of the slice in pixel (px)
Each number within labels represents an individual slice or frame within the data unit. Each slice or frame contains the following:

"labels": {
      "0": {
        "objects": { },
        "classifications": [ ],
        "metadata":{ }
      }
}  
KeyDescriptionNotes
objectsA list of label objects on this sliceContains geometric information for object labels
classificationsA list of classifications applying to the entire slice or frameIs the same value for all instances of this classification.
metadataSlice specific metadata
objects contains label information for all object instances in a frame. A key with the name of the object shape is always present - polygon in the example below. All shapes contain coordinates for each vertex.
Navigate to the ontology shapes section to see how all ontology classes are represented in the exported file.
The example below shows a single object instance.
"objects": [
  {
        "name": "lungs",
        "color": "#D33115",
        "shape":"polygon",
        "value": "lungs",
        "polygon": {
          "0": {
            "x": 0.2423,
            "y": 0.5115,
          },
          "1": {
            "x": 0.4167,
            "y": 0.4218,   
          }
        },
        "createdAt": "Thu, 07 Sep 2023 09:47:35 GMT",
        "createdBy": "david.babuschkin@encord.com",
        "confidence": "1",
        "objectHash": "mQ+yKcF5",
        "featureHash": "pRwpsg1H",
        "manualAnnotation": true
      }
]  
KeyDescriptionNotes
nameThe object’s nameAs specified in the ontology
colorThe color used to draw the objectAs specified in the ontology
shapeThe ontology class used to create the objectAs specified in the ontology
valueThe name given to the object
polygonA list containing the x and y coordinates of each vertex on the polygonRefer to the ontology shapes section for more details
createdAtDate and time the object was created
createdByThe email of the user that created this object
confidenceThe confidence score for this objectA confidence score of 1 is given for all labels created manually. More info can be found here
objectHashThe specific label’s hashThe ‘hash’ represents a unique identifier
featureHashThe ontology object’s hashCorresponds to the FeatureNodeHash in the ontology
manualAnnotationA field indicating whether the object was drawn manually or nottrue means it was drawn manually, while false means it was created using a model or an automated labeling technique
classifications contains all frame level classification information for the slice.The example below shows a single classification instance.
"classifications": [
  {
        "name": "State",
        "value": "state",
        "createdAt":"Tue, 10 Oct 2023 14:16:14 GMT",
        "createdBy": "david.babuschkin@encord.com",
        "confidence": "1",
        "featureHash": "wUS7p9B6",
        "lastEditedAt": "Tue, 10 Oct 2023 14:16:14 GMT",
        "classificationHash": "jiOiEq76",
        "manualAnnotation": true
      }
]  
KeyDescriptionNotes
nameThe classification’s nameAs specified in the ontology
valueThe classification valueSame as the name
createdAtTime and day the classification was created
createdByThe email of the user that created this classification
confidenceThe confidence score for this classificationA confidence score of 1 is given for all labels created manually. More info can be found here
featureHashThe classification instance hashCorresponds to the FeatureNodeHash in the ontology
lastEditedAtTime and date of the last time this classification was edited
classificationHashThe classification instance hash hash
manualAnnotationA field indicating whether the object was drawn manually or nottrue means it was drawn manually, while false means it was created using a model or an automated labeling technique
"metadata": {
      "dicom_instance_uid": "1.3.9.1.4.7.14219.5.2.8.1600.1202.0357967439694942",
      "multiframe_frame_number": "null",
      "file_uri":"cord-dicoms/H7sLTXjYbrou3GhfmHRiuE5m92/5adba3dd-09f6-5c95-b954-e76542fe0ed7",
      "width": "512",
      "height": "512",
}  
KeyDescriptionNotes
dicom_instance_uidThe DICOM instance UIDDICOM tag value (0008,0018). More information can be found here
multiframe_frame_numberA field indicating the frame number when the JSON contains only a single labelDisplays null when each slice has its only expandable labels instance
file_uriThis slice’s URIIdentifies this slice
heightThe slice’s height (in pixel)DICOM tag value (0028,0010). More information can be found here
widthThe slice’s width (in pixel)DICOM tag value (0028,0011). More information can be found here
The slice metadata contains information on the DICOM study, the DICOM series, as well as the patient.
"metadata": {
      "patient_id": "ENC-ORD-LUV-031023",
      "study_uid": "null",
      "series_uid":"cord-dicoms/H7sLTXjYbrou3GhfmHRiuE5m92/5adba3dd-09f6-5c95-b954-e76542fe0ed7",
}  
KeyDescriptionNotes
patient_idThe patient IDDICOM tag value (0010,0020). More information can be found here
study_uidThe DICOM study’s IDDICOM tag value (0020,000D). More information can be found here
series_uidThe DICOM series’ IDDICOM tag value (0020,000E). More information can be found here
object_answers is a list of objects that have at least one nested attribute and contains information for all attributes. Expanding object_answers reveals the following:
"object_answers": {
  "Gqh06ypx"
      "objectHash": "Gqh06ypx",
      "classifications" [ 
        "name": "Size",
        "value": "size",
        "answers": "Medium",
        "featureHash": "GZnFumFq",
        "manualAnnotation": true
      ]
}  
KeyDescriptionNotes
objectHashThe hash of the object containing the attributesThe ‘hash’ represents a unique identifier
classificationsA list of attributes related to the object. Includes Dynamic attributes and Relation attributes.Not to be confused with classifications as defined in our glossary, which apply to a frame
nameThe attribute name
valueThe attribute valueAlways the same as the name
answersThe value(s) the attribute(s) were set toIf the attribute was a radio button, the answer is the option selected by the annotator
featureHashThe attribute’s hashThe ‘hash’ represents a unique identifier
manualAnnotationA field indicating whether the object was drawn manually or nottrue means it was drawn manually, while false means it was created using a model or an automated labeling technique
classification_answers a list of frame classifications in which each classification is represented by its hash. Expanding classification_answers reveals the following:
"classification_answers": {
  "OFX2jzwE": {
    "classificationHash": "OFX2jzwE", 
    "classifications": [{
      "name": "Quality", 
      "value": "quality", 
      "answers": [{
        "name": "out of focus", 
        "value": "out_of_focus", 
        "featureHash": "j/7dpSmi"}],    
    "featureHash": "uZmB5YZC", 
    "manualAnnotation": true
    }]
  }
}
KeyDescriptionNotes
classificationHashThe classification’s hashThe ‘hash’ represents a unique identifier
classificationsA list of information about the classification
nameThe classification nameAs set in the ontology (Quality in the example above)
valueThe classification valueAlways the same as the classification name
answersA list of all classification answers”answers” refer to the values the classification were set to.
nameThe name of the classification answer”out of focus” in the example above
valueThe classification answer’s valueAlways the same as the classification answer’s name
featureHashThe hash for the particular classification answerIncluded in answers
featureHashThe hash for the particular classification
manualAnnotationtrue for all manually created labels. false for all labels created with automated labeling techniques
The export_history contains a list of all exports for this data unit, the first entry being the current export. Each instance contains the following:
"export_history": {
  "0"
      "export_hash": "Gqh06ypx",
      "exported_at": "Mon, 02 Oct 2023 13:47:45 UTC",
      "user_email": "david.babuschkin@encord.com"
}  
KeyDescriptionNotes
export_hashThe export instance’s hashThe ‘hash’ represents a unique identifier
exported_atDate and time of the export
user_emailThe email of the user that made this export

Audio

The export contains a list of JSON objects, with each JSON object representing a single data unit and containing detailed information for all exported labels. The example below describes all the keys for a single exported data unit.
[
    {
        "classification_answers": {},
        "created_at": "2025-01-09 15:58:20",
        "data_hash": "ffd810f4-f503-46ac-b54f-bd5f8057f440",
        "data_title": "beautiful-tune.mp3",
        "data_type": "audio",
        "data_units": {
        },
        "dataset_hash": "3696067a-7e68-4d25-b09d-517877e13f06",
        "dataset_title": "Music",
        "is_image_sequence": null,
        "is_valid": true,
        "label_hash": "a384bab6-9443-4932-a862-c5c18f39c88b",
        "label_status": "LABELLED",
        "last_edited_at": "2025-01-09 15:58:35",
        "object_actions": {},
        "object_answers": {}
    }
]
KeyDescriptionNotes
label_hashThe Label Row hashThe ‘hash’ represents a unique identifier
created_atTime and date the label was created
last_edited_atTime and date the label was last edited
dataset_hashThe Dataset’s hashThe ‘hash’ represents a unique identifier
data_typeThe data unit’s file formatAlways “video” for videos
is_image_sequence”true” when the data unit is an image sequenceAlways “null” for images
video_linkContains a private cloud URL for videosAlways “null” for images
data_unitsList of all files the data unit is composed ofDetails of the export information for `data_units“ can be found below.
object_answersAll the attributes in this data unitThe object attributes are identified using their hash
classification_answersAll the classifications in a particular data unitThe classification labels are identified using their hash
object_actionsThe number of states a dynamic attribute can be in.A change in state occurs each time the attribute answer changes. The objectHash within the object_actions is the attribute answer’s ID.
label_statusIndicates whether the data unit has been labeled.
export_historyContains a record of the export history for this data unitExporting labels to confirm export history generates an export history entry.
export_hashThe hash for this particular export instanceThe ‘hash’ represents a unique identifier
exported_atThe date and time when a particular export instance took place.
classification_answers a list of frame classifications in which each classification is represented by its hash. Expanding classification_answers reveals the following:
"classification_answers": {
    "yRY6RT5j": {
        "classificationHash": "yRY6RT5j",
        "classifications": [
            {
                "answers": [
                    {
                        "featureHash": "h6dn9yfZ",
                        "name": "No ",
                        "value": "no_"
                    }
                ],
                "featureHash": "+n1+XoVr",
                "manualAnnotation": true,
                "name": "Good Song?",
                "value": "good_song?"
            }
        ],
        "confidence": null,
        "createdAt": "Thu, 09 Jan 2025 15:58:27 GMT",
        "createdBy": "david.babuschkin@encord.com",
        "featureHash": "lQS4psvP",
        "lastEditedAt": "Thu, 09 Jan 2025 15:58:27 GMT",
        "lastEditedBy": "david.babuschkin@encord.com",
        "manualAnnotation": true,
        "range": [
            [
                0,
                132963
            ]
        ]
    }
},
KeyDescriptionNotes
classificationHashThe classification’s hashThe ‘hash’ represents a unique identifier
classificationsA list of information about the classification
nameThe classification nameAs set in the ontology (Quality in the example above)
valueThe classification valueAlways the same as the classification name
answersA list of all classification answers”answers” refer to the values the classification were set to.
nameThe name of the classification answer”out of focus” in the example above
valueThe classification answer’s valueAlways the same as the classification answer’s name
featureHashThe hash for the particular classification answerIncluded in answers
featureHashThe hash for the particular classification
manualAnnotationtrue for all manually created labels. false for all labels created with automated labeling techniques
rangeThe time span on which the classification label is appliedMeasured in milliseconds (ms)
The data_units key contains all files that compose the data unit. For a given image there is only ever a single element in this list. This element contains the following information.
data_units here refer to individual files that compose a data unit, as defined in our glossary, and are not to be confused with data units elsewhere in the platform. Encord will update this nomenclature soon, but we always communicate changes to all customers first.
"data_units": {
  "ffd810f4-f503-46ac-b54f-bd5f8057f440": {
      "audio_bit_depth": 32,
      "audio_codec": "mp3float",
      "audio_num_channels": 2,
      "audio_sample_rate": 44100,
      "data_duration": 132.96327,
      "data_hash": "ffd810f4-f503-46ac-b54f-bd5f8057f440",
      "data_link": "gs://cord-ai-platform.appspot.com/cord-audio-prod/iaDJxNNrMuQMtFPcP9oszw2OCHm2/6e235f70-8ade-4bb6-8d76-d3010d7deda3",
      "data_sequence": 0,
      "data_title": "beautiful-tune.mp3",
      "data_type": "audio/mpeg",
      "labels": {}
  }
}
KeyDescriptionNotes
data_hashThe file’s hashThe ‘hash’ represents a unique identifier
data_titleThe file’s title
data_typeThe file type
data_sequenceThe sequence number of this file within the data unitAlways 0 for images, as single images are composed of a single file by definition
labelsA container for the image’s label informationThis contains the label information for the image.
data_linkA link to the file stored in your private cloud
widthThe width of the image in pixel (px)
heightThe height of the image in pixel (px)
object_answers contains all the object labels that have at least one nested attribute and contains information for all attributes. Expanding object_answers reveals the following:
"object_answers": {
    "zcmSZzvI": {
        "classifications": [],
        "confidence": null,
        "createdAt": "Thu, 09 Jan 2025 15:58:24 GMT",
        "createdBy": "david.babuschkin@encord.com",
        "featureHash": "1uLJrW4C",
        "lastEditedAt": "Thu, 09 Jan 2025 15:58:24 GMT",
        "lastEditedBy": "david.babuschkin@encord.com",
        "manualAnnotation": true,
        "objectHash": "zcmSZzvI",
        "range": [
                    [
                        14287,
                        51843
                    ]
        ]
    }
}
KeyDescriptionNotes
objectHashThe hash of the object containing the attributesThe ‘hash’ represents a unique identifier
classificationsA list of attributes related to the object.Not to be confused with classifications as defined in our glossary, which apply to a frame
nameThe attribute name
valueThe attribute valueAlways the same as the name
answersThe value(s) the attribute(s) were set toIf the attribute was a radio button, the answer is the option selected by the annotator
featureHashThe attribute’s hashThe ‘hash’ represents a unique identifier
manualAnnotationA field indicating whether the object was drawn manually or nottrue means it was drawn manually, while false means it was created using a model or an automated labeling technique
rangeThe time span on which the object label is appliedMeasured in milliseconds (ms)

Text

The export contains a list of JSON objects, with each JSON object representing a single data unit and containing detailed information for all exported labels. The example below describes all the keys for a single exported data unit.
[
    {
        "classification_answers": {},
        "created_at": "2025-01-11 14:58:20",
        "data_hash": "ffd810f4-f503-46ac-b54f-bd5f8057f440",
        "data_title": "encord-website.html",
        "data_type": "plain_text",
        "data_units": {
        },
        "dataset_hash": "3696067a-7e68-4d25-b09d-517877e13f06",
        "dataset_title": "HTML Text",
        "is_image_sequence": null,
        "is_valid": true,
        "label_hash": "a384bab6-9443-4932-a862-c5c18f39c88b",
        "label_status": "LABELLED",
        "last_edited_at": "2025-01-09 15:58:35",
        "object_actions": {},
        "object_answers": {}
    }
]
KeyDescriptionNotes
label_hashThe Label Row hashThe ‘hash’ represents a unique identifier
created_atTime and date the label was created
last_edited_atTime and date the label was last edited
dataset_hashThe Dataset’s hashThe ‘hash’ represents a unique identifier
data_typeThe data unit’s file formatAlways “video” for videos
is_image_sequence”true” when the data unit is an image sequenceAlways “null” for images
video_linkContains a private cloud URL for videosAlways “null” for images
data_unitsList of all files the data unit is composed ofDetails of the export information for `data_units“ can be found below.
object_answersAll the attributes in this data unitThe object attributes are identified using their hash
classification_answersAll the classifications in a particular data unitThe classification labels are identified using their hash
object_actionsThe number of states a dynamic attribute can be in.A change in state occurs each time the attribute answer changes. The objectHash within the object_actions is the attribute answer’s ID.
label_statusIndicates whether the data unit has been labeled.
export_historyContains a record of the export history for this data unitExporting labels to confirm export history generates an export history entry.
export_hashThe hash for this particular export instanceThe ‘hash’ represents a unique identifier
exported_atThe date and time when a particular export instance took place.
classification_answers a list of frame classifications in which each classification is represented by its hash. Expanding classification_answers reveals the following:
"classification_answers": {
    "EpcchMiS": {
        "classificationHash": "EpcchMiS",
        "classifications": [
            {
                "answers": [
                    {
                        "featureHash": "4EbpTJ8E",
                        "name": "Single Extension",
                        "value": "single_extension"
                    }
                ],
                "featureHash": "/Kt0x2uF",
                "manualAnnotation": true,
                "name": "HTML Type",
                "value": "html_type"
            }
        ],
        "confidence": null,
        "createdAt": "Tue, 07 Jan 2025 12:25:12 GMT",
        "createdBy": "david.babuschkin@encord.com",
        "featureHash": "yboRL9Pm",
        "lastEditedAt": "Tue, 07 Jan 2025 12:25:12 GMT",
        "lastEditedBy": "david.babuschkin@encord.com",
        "manualAnnotation": true,
        "range": [
            [
                0,
                0
            ]
        ]
    }
}
KeyDescriptionNotes
classificationHashThe classification’s hashThe ‘hash’ represents a unique identifier
classificationsA list of information about the classification
nameThe classification nameAs set in the ontology (Quality in the example above)
valueThe classification valueAlways the same as the classification name
answersA list of all classification answers”answers” refer to the values the classification were set to.
nameThe name of the classification answer”out of focus” in the example above
valueThe classification answer’s valueAlways the same as the classification answer’s name
featureHashThe hash for the particular classification answerIncluded in answers
featureHashThe hash for the particular classification
manualAnnotationtrue for all manually created labels. false for all labels created with automated labeling techniques
rangeThe frame range on which the classification label is applied
The data_units key contains all files that compose the data unit. For a given image there is only ever a single element in this list. This element contains the following information.
data_units here refer to individual files that compose a data unit, as defined in our glossary, and are not to be confused with data units elsewhere in the platform. Encord will update this nomenclature soon, but we always communicate changes to all customers first.
"data_units": {
  "ffd810f4-f503-46ac-b54f-bd5f8057f440": {
      "audio_bit_depth": 32,
      "audio_codec": "mp3float",
      "audio_num_channels": 2,
      "audio_sample_rate": 44100,
      "data_duration": 132.96327,
      "data_hash": "ffd810f4-f503-46ac-b54f-bd5f8057f440",
      "data_link": "gs://cord-ai-platform.appspot.com/cord-audio-prod/iaDJxNNrMuQMtFPcP9oszw2OCHm2/6e235f70-8ade-4bb6-8d76-d3010d7deda3",
      "data_sequence": 0,
      "data_title": "beautiful-tune.mp3",
      "data_type": "audio/mpeg",
      "labels": {}
  }
}
KeyDescriptionNotes
data_hashThe file’s hashThe ‘hash’ represents a unique identifier
data_titleThe file’s title
data_typeThe file type
data_sequenceThe sequence number of this file within the data unitAlways 0 for images, as single images are composed of a single file by definition
labelsA container for the image’s label informationThis contains the label information for the image.
data_linkA link to the file stored in your private cloud
widthThe width of the image in pixel (px)
heightThe height of the image in pixel (px)
object_answers contains all the object labels that have at least one nested attribute and contains information for all attributes. Expanding object_answers reveals the following:
"object_answers": {
    "YFfOG14v": {
        "classifications": [],
        "confidence": null,
        "createdAt": "Tue, 07 Jan 2025 12:25:36 GMT",
        "createdBy": "david.babuschkin@encord.com",
        "featureHash": "AZfKc9b7",
        "lastEditedAt": "Tue, 07 Jan 2025 12:25:36 GMT",
        "lastEditedBy": "david.babuschkin@encord.com",
        "manualAnnotation": true,
        "objectHash": "YFfOG14v",
        "range": [],
        "range_html": [
            {
                "end": {
                    "node": "/html[1]/body[1]/div[1]/div[1]/div[1]/main[1]/div[2]/div[1]/section[1]/section[1]/article[1]/section[1]/section[1]/p[1]/text()[1]",
                    "offset": 245
                },
                "start": {
                    "node": "/html[1]/body[1]/div[1]/div[1]/div[1]/main[1]/div[2]/div[1]/section[1]/section[1]/article[1]/section[1]/section[1]/p[1]/text()[1]",
                    "offset": 125
                }
            }
        ]
    }
}
KeyDescriptionNotes
objectHashThe hash of the object containing the attributesThe ‘hash’ represents a unique identifier
classificationsA list of attributes related to the object.Not to be confused with classifications as defined in our glossary, which apply to a frame
nameThe attribute name
valueThe attribute valueAlways the same as the name
answersThe value(s) the attribute(s) were set toIf the attribute was a radio button, the answer is the option selected by the annotator
featureHashThe attribute’s hashThe ‘hash’ represents a unique identifier
manualAnnotationA field indicating whether the object was drawn manually or nottrue means it was drawn manually, while false means it was created using a model or an automated labeling technique
rangeThe frame range on which the object label is applied
range_htmlProvides detailed information about the specific section of the text file being labeled
startStart point of the label
endEnd point of the label
offsetAn integer that specifies the character position within the identified nodeFor example { "offset": 125 } means the label starts / ends at the 125th character in the node

Ontology Shapes

Exports contain the Ontology shape coordinates used to create the label.
x and y represent coordinates of the top-left corner of the box. h and w respectively represent the height and width of the box.
 "boundingBox": {
    "h": 0.118,
    "w": 0.1643,
    "x": 0.6985,
    "y": 0.6204
 }
This is a legacy field used by existing customers. We recommend new customers use the polygons field below.
The polygon list contains the x and y coordinates for all vertices in a simple polygon. For complex polygons, see the polygons field below.
"polygon": {
  "0": {
    "x": 0.2423,
    "y": 0.5115,
  },
  "1": {
    "x": 0.4167,
    "y": 0.4218,   
          },
  "2": {
    "x": 0.5821,
    "y": 0.4641,   
          },
  "3": {
    "x": 0.5808,
    "y": 0.5756,   
          },
  "4": {
    "x": 0.4564,
    "y": 0.6397,   
          }
  }

Polygons can have complex shapes, including being enclosed in one another, and encompassing separate regions. In each case the polygon’s coordinates are arranged in a different way.
Polylines contain the x and y coordinates for each vertex.
 "polyline": {
  "0": {
    "x": 0.2423,
    "y": 0.5115,
  },
  "1": {
    "x": 0.4167,
    "y": 0.4218,   
          },
  "2": {
    "x": 0.5821,
    "y": 0.4641,   
          },
  "3": {
    "x": 0.5808,
    "y": 0.5756,   
          },
  "4": {
    "x": 0.4564,
    "y": 0.6397,   
          }
  }

Keypoints are represented in the export using only x and y coordinates.
 "point": {
    "0": {
      "x": 0.3192,
      "y": 0.1547,
  }
 }
x and y represent the coordinates of the top-left corner of the unrotated box. h and w respectively represent the height and width of the box, while theta represents the angle of clockwise rotation of the bounding box about the center of the box.
 "rotatableBoundingBox": {
    "h": 0.118,
    "w": 0.1643,
    "x": 0.6985,
    "y": 6204,
    "theta": 305.7762
 }
The rleString encodes the Bitmask label, and has to be decoded. See our SDK documentation to learn how to decode an rleString.
"objects": [
      {
        "bitmask": {
          "rleString": "02220N:0F20N",
          "top": 0,
          "left": 0,
          "width": 6,
          "height": 6
        }
      }
  ]  
Object primitives are referred to as skeletons in the export. Each point on the object primitive is represented in the export using x and y coordinates.Below is an example of an object primitive with 3 points.

"skeleton": {
  "0": {
    "x": 0.5719,
    "y": 0.7615,
    "name": "point_0",
    "color": "#fcc400",
    "value": "point_0",
    "featureHash": "qPCTeIci"
    },
    "1": {
    "x": 0.5428,
    "y": 0.6734,
    "name": "point_1",
    "color": "#fcc400",
    "value": "point_1",
    "featureHash": "o1NKWqKP",
    "invisible": true
    },
    "2": {
    "x": 0.4865,
    "y": 0.6464,
    "name": "point_2",
    "color": "#fcc400",
    "value": "point_2",
    "featureHash": "9bgJBA85",
    "occluded": true
    }
}

KeyDescriptionNotes
nameName of this pointAs set in the Ontology
colorThe hexadecimal color code used to represent this pointAs set in the Ontology
featureHashThe hash for this particular pointthe ‘hash’ is a unique identifier
occludedThis point is marked as occludedif the point was left on the default setting (visible) this key is omitted
invisibleThis point is marked as invisibleif the point was left on the default setting (visible) this key is omitted

Exporting Bitmasks

Bitmask labels are exported as rleStrings. See our SDK documentation to learn how to decode an rleString.
We strongly recommend exporting Bitmask labels using the Encord SDK. Bitmasks are exported in the JSON format.

Exporting Data Groups

When exporting Data Group labels, 1 JSON file the Data Group plus 1 JSON for each data unit in the Data Group are generated.
Data Groups Label Export
[
    {
        "label_hash": "5eac2bd5-dbd1-4a45-9d80-d70d3d383e37",
        "branch_name": "main",
        "created_at": "2025-06-05 13:26:03",
        "last_edited_at": "2025-06-05 13:26:03",
        "dataset_hash": "f51bccba-17fd-4fc6-90b2-688b453cd728",
        "dataset_title": "Data groups - Fruit",
        "data_title": "Data group - Blueberries and Cherries",
        "data_hash": "52a9df9f-b498-4162-ae2b-7eeaf478c592",
        "data_type": "group",
        "is_image_sequence": null,
        "data_units": {
            "52a9df9f-b498-4162-ae2b-7eeaf478c592": {
                "data_hash": "52a9df9f-b498-4162-ae2b-7eeaf478c592",
                "data_title": "Data group - Blueberries and Cherries",
                "data_type": "application/vnd.encord.data.group",
                "data_sequence": 0,
                "labels": {},
                "metadata": {
                    "children": [
                        {
                            "data_hash": "9c4c647f-1f10-4c4c-8a01-9e58769f3992",
                            "name": "Blueberries-001.mp4",
                            "label_hash": "e8dac7b3-f0dc-43e9-b073-d570c05cb829",
                            "layout_key": "0"
                        },
                        {
                            "data_hash": "1c35ff88-d015-49ef-b370-d421ba2d0923",
                            "name": "Blueberries-002.mp4",
                            "label_hash": "254e678a-2054-4c0e-a8e8-c7dd738f8c6a",
                            "layout_key": "1"
                        },
                        {
                            "data_hash": "62ebe621-3f40-4311-b93e-e97897fcd688",
                            "name": "Cherries-001.mp4",
                            "label_hash": "09253f83-a9d7-4465-ae4f-ac22d8a00066",
                            "layout_key": "2"
                        },
                        {
                            "data_hash": "970b40ae-e4d5-4742-8e56-ff2807d02b5a",
                            "name": "Cherries-002.mp4",
                            "label_hash": "64443b3c-5388-4b9e-919a-94295206a2fa",
                            "layout_key": "3"
                        }
                    ]
                }
            }
        },
        "object_answers": {},
        "classification_answers": {},
        "object_actions": {},
        "label_status": "LABEL_IN_PROGRESS",
        "is_valid": true,
        "video_link": null
    }
]
KeyDescriptionNotes
label_hashThe Label Row hashThe ‘hash’ represents a unique identifier
branch_nameThe branch the label belongs tomain is the default branch in non-Consensus Projects
created_atTime and date the label was created
last_edited_atTime and date the label was last edited
dataset_hashThe Dataset’s hashThe ‘hash’ represents a unique identifier
dataset_titleThe name of the Dataset
data_titleThe Data Group’s name
data_typeThe data unit’s file formatAlways group for Data Groups
is_image_sequence”true” when the data unit is an image sequenceAlways “null” for Data Groups
data_unitsList of all files the Data Group is composed ofDetails of the export information for data_units can be found below
data_hashThe Data Group hash.The ‘hash’ represents a unique identifier for the Data Group
data_titleThe Data Group’s name
data_typeThe data unit’s file formatAlways group for Data Groups
data_sequenceThe sequence number of this file within the data unit.0 represents the first file
labelsA list of all frames contained in the Data GrouopThis value is always 0
metadataLists the metadata on the Data Group
childrenlists the data units contained in the Data Grouplayout_key specifies where in the Data Group the data units appears in the Label Editor
object_answersAll the attributes in this data unitThe object attributes are identified using their hash
classification_answersAll the classifications in a particular data unitThe classification labels are identified using their hash
object_actionsThe number of states a dynamic attribute can be in.A change in state occurs each time the attribute answer changes. The objectHash within the object_actions is the attribute answer’s ID.
label_statusIndicates whether the data unit has been labeled.
is_validIndicates whether the Data Group is valid
video_linkLink to the video saved on your private cloudAlways “null” for Data Groups

Exporting Labels using the SDK

Go here to learn how to export labels using SDK.

Label Branches

The branch associated with the labels is specified using the branch_name key. The main branch is always displayed first and is identified by the following value:
"branch_name": "main"
I