> ## Documentation Index
> Fetch the complete documentation index at: https://docs.cockroachlabs.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Well Known Binary

The Well Known Binary format (hereafter *WKB*) provides a non-textual, binary representation of a geometric shape. It is used to:

* Allow shapes to be transferred between CockroachDB and a [SQL client](/docs/stable/cockroach-sql.md) or [application](/docs/stable/build-a-java-app-with-cockroachdb.md).
* Provide a portable binary format that can be read across different platforms.

WKB is obtained by serializing a shape as a sequence of numbers. For more detailed information about the structure of the WKB format, see the diagrams showing WKB integer codes in the [OpenGIS Implementation Specification for Geographic information - Simple feature access - Part 1: Common architecture](https://portal.opengeospatial.org/files/?artifact_id=25355).

The Extended Well Known Binary (*EWKB*) format is the same as WKB, with an [SRID](/docs/stable/architecture/glossary.md#srid) representation prepended to the data structure.

## See also

* [Spatial Data Overview](/docs/stable/spatial-data-overview.md)
* [Spatial indexes](/docs/stable/spatial-indexes.md)
* [Spatial and GIS Glossary of Terms](/docs/stable/architecture/glossary.md)
* [OpenGIS Implementation Specification for Geographic information - Simple feature access - Part 1: Common architecture](https://portal.opengeospatial.org/files/?artifact_id=25355)
* [Well known text](/docs/stable/well-known-text.md)
* [GeoJSON](/docs/stable/geojson.md)
* [SRID 4326 - longitude and latitude](/docs/stable/srid-4326.md)
* [Introducing Distributed Spatial Data in CockroachDB](https://www.cockroachlabs.com/blog/spatial-data/) (blog post)