Metadata
Instructions for adding, filtering, and modifying metadata in the app UI.
Developer guide: Metadata
Metadata is non-annotation information about an asset. You can use metadata to search and filter your data rows in Labelbox. The metadata schema lives at the organization level. This allows you to apply the same metadata fields across multiple datasets.
There are two types of metadata: reserved fields (user cannot change) and custom (user-defined) fields.
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.
Name | Type |
---|---|
tag | Free text field |
split | Enum - [train, valid, test] |
captureDateTime | ISO 8601 datetime field. All times must be in UTC |
embedding | A 128 length list 32 bit floats used for similarity search. All datarows share the same similarity index |
Custom fields
All metadata is strictly typed. These are the custom fields Labelbox offers.
Type | Notes | Filtering |
---|---|---|
String | free text field. Max 4096 characters. | Equals & prefix matching |
Enum | Enum field with options. Multiple options can be imported. | 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 |
DateTime | An ISO 8601 datetime field. All times must be in UTC timezone | Equals, greater than, less than, between |
Embedding | 128 float 32 vector used for similarity |
To view your metadata schema, go to the Schema tab and click on the Metadata subtab.

Create custom metadata schema via the UI
To create custom metadata fields via the UI, go to the Schema tab. Click Create.

Each metadata field must have a unique name and a type. The max number of fields per organization is determined by account tier.

Metadata field limit
Know your account limits of maximum number of allowed metadata fields.
Once you create a field, you cannot change the type. You can modify the names of custom metadata schema by clicking the Edit button in the detail view of each schema. You cannot modify the names of reserved fields.
Bulk add metadata
Follow these steps to bulk add metadata to your data rows in the Catalog UI.
Limits
See this page to learn the limits for bulk adding metadata to data rows in Catalog.
Step 1: Select data rows
You will need to select a curate a subset of data.
For example, you may select a cluster of data from the projector view. Another option could be to select the top results of a natural language search. This way, you can use neural networks like CLIP as zero-shot classifiers. A third possibility is to select all assets that look similar to each other - thanks to Labelbox similarity search. Similarity search powered by embeddings allows you to leverage any off-the-shelf neural network as a zero-shot classifier.
There are three ways to select data rows:
- Option 1: Click on Select all to select all filtered data rows.
- Option 2: Manually select data rows by clicking on the selection icon in the top left of the thumbnail.
- Option 3: Bulk select data rows by selecting the first data row, then
shift
and select the last data row. All data rows between the first and last ones will be selected.

In this example, we select all data rows containing the keyword "happy"
Step 2: Add metadata
After you select your data rows, click Add metadata.

Step 3: Pick a metadata field
From the dropdown menu, pick the metadata field you want to apply. You can search for metadata fields by typing their name if you don't see them in the dropdown. A metadata field must exist in Labelbox, to show up in the dropdown.

Step 4: Provide metadata values
Enter a metadata value. This metadata field and value will apply to all selected data rows.
Click on Save to apply the metadata in bulk. It typically takes a few seconds to a few minutes for the metadata to show up on the data rows.

We tag all data rows that contain the keyword "happy" as Sentiment > Positive
View metadata
You can surface data rows with the new metadata values, by searching on metadata in Labelbox.

We surface all data rows with the metadata field "Sentiment" and value "Positive"
The newly created metadata tag will also show up in the detailed view.

Filter metadata
Once you upload your metadata, you can easily filter and view metadata in Catalog. If you want to label this set of data rows, you can filter by that metadata field and send them to a labeling project as a batch.
Metadata viewing access
Labelers cannot filter and view metadata in Catalog. However, labelers will be able to view metadata information in the data row information panel.

Click on any data row to open the detailed view. There you can find the metadata for that asset.

Export metadata
When you export your metadata, you can sync the newly created metadata with any outside system such as a cloud bucket, data lake, data warehouse, or database. To learn how to export data rows containing metadata, see Export from catalog.
Delete metadata
You can delete metadata for a data row through the SDK. Visit this guide for instructions.
Updated about 1 month ago