﻿---
title: ES|QL ST_BUFFER function
description: 
url: https://www.elastic.co/elastic/docs-builder/docs/3002/reference/query-languages/esql/functions-operators/spatial-functions/st_buffer
products:
  - Elasticsearch
---

# ES|QL ST_BUFFER function
<applies-to>
  - Elastic Cloud Serverless: Preview
  - Elastic Stack: Planned
</applies-to>


## Syntax

![Embedded](https://www.elastic.co/elastic/docs-builder/docs/3002/reference/query-languages/esql/images/functions/st_buffer.svg)


## Parameters

<definitions>
  <definition term="geometry">
    Expression of type `geo_point`, `geo_shape`, `cartesian_point` or `cartesian_shape`. If `null`, the function returns `null`.
  </definition>
  <definition term="distance">
    Buffer distance in the units of the input spatial reference system
  </definition>
</definitions>


## Description

Computes a buffer area around the input geometry at the specified distance. The distance is in the units of the input spatial reference system. Positive distances expand the geometry, negative distances shrink it. Points and lines become polygons when buffered.

## Supported types


| geometry        | distance | result          |
|-----------------|----------|-----------------|
| cartesian_point | double   | cartesian_shape |
| cartesian_point | float    | cartesian_shape |
| cartesian_point | integer  | cartesian_shape |
| cartesian_point | long     | cartesian_shape |
| cartesian_shape | double   | cartesian_shape |
| cartesian_shape | float    | cartesian_shape |
| cartesian_shape | integer  | cartesian_shape |
| cartesian_shape | long     | cartesian_shape |
| geo_point       | double   | geo_shape       |
| geo_point       | float    | geo_shape       |
| geo_point       | integer  | geo_shape       |
| geo_point       | long     | geo_shape       |
| geo_shape       | double   | geo_shape       |
| geo_shape       | float    | geo_shape       |
| geo_shape       | integer  | geo_shape       |
| geo_shape       | long     | geo_shape       |


## Example

```esql
ROW wkt = "POLYGON ((0 0, 4 0, 4 4, 0 4, 0 0))"
| EVAL buffered = ST_BUFFER(TO_GEOSHAPE(wkt), -1)
```


| wkt:keyword                         | buffered:geo_shape                                      |
|-------------------------------------|---------------------------------------------------------|
| POLYGON ((0 0, 4 0, 4 4, 0 4, 0 0)) | POLYGON ((1.0 1.0, 1.0 3.0, 3.0 3.0, 3.0 1.0, 1.0 1.0)) |