Defining custom metadata fields

Metadata is non-annotation information about the asset to be labeled. You can use metadata to search and filter across your data rows in Labelbox.

There are two types of metadata: reserved fields (user cannot change) and custom (user-defined) fields.

Metadata schema

The metadata schema lives at the organization level, allowing you to apply the same metadata fields across multiple datasets. To view your metadata schema, go to the Schema tab and click on the Metadata subtab.


Attachments vs metadata

In an earlier version of Labelbox, what is now called attachments used to be called metadata. Attachments provide additional context for labelers but are not searchable within Catalog.

Reserved fields

Upon upload, Labelbox automatically defines a set of reserved fields on your data rows to help you easily access the full range of features in Labelbox. Each metadata field has a unique schema ID that is used to upload data to Labelbox.

tagFree text field
embeddingAn embedding field
splitEnum - [train, valid, test]
captureDateTimeISO 8601 datetime field. All times must be in UTC
precomputedImageEmbeddingEmbedding computed for uploaded image data
precomputedTextEmbeddingEmbedding computed for uploaded text data

Custom fields

All metadata is strictly typed. These are the custom fields Labelbox offers.

EmbeddingUsed for similarity. A float vector of length 128Similarity
Stringfree text field. Max 1024 characters.Equals & prefix matching
EnumEnum field with options.Equals
Option (Enum)Option of an enum. Max 64 options can be created per Enum type. 128 for enterprise customers and can be further increased upon request.Equals
DateTimeAn ISO 8601 datetime field. All times must be in UTC timezoneEquals, greater than, less than, between
NumberInteger or FloatEquals, greater than, less than, between


Can labelers see metadata?

Yes, labelers can see metadata from the data row information panel. For more details, please refer to the page Data row Information panel.

Can metadata be used to customize the queue?

Not directly. But you could use the Catalog to query a set of data rows that have specific metadata in common and add to the project for labeling using Batch queue (beta) .

What’s Next