﻿---
title: Filters aggregation
description: A multi-bucket aggregation where each bucket contains the documents that match a query. Example: In the above example, we analyze log messages. The aggregation...
url: https://www.elastic.co/elastic/docs-builder/docs/2666/reference/aggregations/search-aggregations-bucket-filters-aggregation
products:
  - Elasticsearch
---

# Filters aggregation
A multi-bucket aggregation where each bucket contains the documents that match a [query](https://www.elastic.co/elastic/docs-builder/docs/2666/reference/query-languages/querydsl).
Example:

```json

{ "index" : { "_id" : 1 } }
{ "body" : "warning: page could not be rendered" }
{ "index" : { "_id" : 2 } }
{ "body" : "authentication error" }
{ "index" : { "_id" : 3 } }
{ "body" : "warning: connection timed out" }


{
  "size": 0,
  "aggs" : {
    "messages" : {
      "filters" : {
        "filters" : {
          "errors" :   { "match" : { "body" : "error"   }},
          "warnings" : { "match" : { "body" : "warning" }}
        }
      }
    }
  }
}
```

In the above example, we analyze log messages. The aggregation will build two collection (buckets) of log messages - one for all those containing an error, and another for all those containing a warning.
Response:
```json
{
  "took": 9,
  "timed_out": false,
  "_shards": ...,
  "hits": ...,
  "aggregations": {
    "messages": {
      "buckets": {
        "errors": {
          "doc_count": 1
        },
        "warnings": {
          "doc_count": 2
        }
      }
    }
  }
}
```


## Anonymous filters

The filters field can also be provided as an array of filters, as in the following request:

```json

{
  "size": 0,
  "aggs" : {
    "messages" : {
      "filters" : {
        "filters" : [
          { "match" : { "body" : "error"   }},
          { "match" : { "body" : "warning" }}
        ]
      }
    }
  }
}
```

The filtered buckets are returned in the same order as provided in the request. The response for this example would be:
```json
{
  "took": 4,
  "timed_out": false,
  "_shards": ...,
  "hits": ...,
  "aggregations": {
    "messages": {
      "buckets": [
        {
          "doc_count": 1
        },
        {
          "doc_count": 2
        }
      ]
    }
  }
}
```


## `Other` Bucket

The `other_bucket` parameter can be set to add a bucket to the response which will contain all documents that do not match any of the given filters. The value of this parameter can be as follows:
<definitions>
  <definition term="false">
    Does not compute the `other` bucket
  </definition>
  <definition term="true">
    Returns the `other` bucket either in a bucket (named `_other_` by default) if named filters are being used, or as the last bucket if anonymous filters are being used
  </definition>
</definitions>

The `other_bucket_key` parameter can be used to set the key for the `other` bucket to a value other than the default `_other_`. Setting this parameter will implicitly set the `other_bucket` parameter to `true`.
The following snippet shows a response where the `other` bucket is requested to be named `other_messages`.

```json

{
  "body": "info: user Bob logged out"
}


{
  "size": 0,
  "aggs" : {
    "messages" : {
      "filters" : {
        "other_bucket_key": "other_messages",
        "filters" : {
          "errors" :   { "match" : { "body" : "error"   }},
          "warnings" : { "match" : { "body" : "warning" }}
        }
      }
    }
  }
}
```

The response would be something like the following:
```json
{
  "took": 3,
  "timed_out": false,
  "_shards": ...,
  "hits": ...,
  "aggregations": {
    "messages": {
      "buckets": {
        "errors": {
          "doc_count": 1
        },
        "warnings": {
          "doc_count": 2
        },
        "other_messages": {
          "doc_count": 1
        }
      }
    }
  }
}
```


## Non-keyed Response

By default, the named filters aggregation returns the buckets as an object. But in some sorting cases, such as [bucket sort](https://www.elastic.co/elastic/docs-builder/docs/2666/reference/aggregations/search-aggregations-pipeline-bucket-sort-aggregation), the JSON doesn’t guarantee the order of elements in the object. You can use the `keyed` parameter to specify the buckets as an array of objects. The value of this parameter can be as follows:
<definitions>
  <definition term="true">
    (Default) Returns the buckets as an object
  </definition>
  <definition term="false">
    Returns the buckets as an array of objects
  </definition>
</definitions>

<note>
  This parameter is ignored by [Anonymous filters](#anonymous-filters).
</note>

Example:

```json

{
  "aggs": {
    "the_filter": {
      "filters": {
        "keyed": false,
        "filters": {
          "t-shirt": { "term": { "type": "t-shirt" } },
          "hat": { "term": { "type": "hat" } }
        }
      },
      "aggs": {
        "avg_price": { "avg": { "field": "price" } },
        "sort_by_avg_price": {
          "bucket_sort": { "sort": { "avg_price": "asc" } }
        }
      }
    }
  }
}
```

Response:
```json
{
  "aggregations": {
    "the_filter": {
      "buckets": [
        {
          "key": "t-shirt",
          "doc_count": 3,
          "avg_price": { "value": 128.33333333333334 }
        },
        {
          "key": "hat",
          "doc_count": 3,
          "avg_price": { "value": 150.0 }
        }
      ]
    }
  }
}
```