elasticsearch/docs/reference/query-dsl/fuzzy-query.asciidoc

[[query-dsl-fuzzy-query]]
=== Fuzzy query
++++
<titleabbrev>Fuzzy</titleabbrev>
++++

Returns documents that contain terms similar to the search term, as measured by
a http://en.wikipedia.org/wiki/Levenshtein_distance[Levenshtein edit distance].

An edit distance is the number of one-character changes needed to turn one term
into another. These changes can include:

* Changing a character (**b**ox → **f**ox)
* Removing a character (**b**lack → lack)
* Inserting a character (sic → sic**k**)
* Transposing two adjacent characters (**ac**t → **ca**t)

To find similar terms, the `fuzzy` query creates a set of all possible
variations, or expansions, of the search term within a specified edit distance.
The query then returns exact matches for each expansion.

[[fuzzy-query-ex-request]]
==== Example requests

[[fuzzy-query-ex-simple]]
===== Simple example

[source,js]
----
GET /_search
{
    "query": {
        "fuzzy": {
            "user": {
                "value": "ki"
            }
        }
    }
}
----
// CONSOLE

[[fuzzy-query-ex-advanced]]
===== Example using advanced parameters

[source,js]
----
GET /_search
{
    "query": {
        "fuzzy": {
            "user": {
                "value": "ki",
                "fuzziness": "AUTO",
                "max_expansions": 50,
                "prefix_length": 0,
                "transpositions": true,
                "rewrite": "constant_score"
            }
        }
    }
}
----
// CONSOLE

[[fuzzy-query-top-level-params]]
==== Top-level parameters for `fuzzy`
`<field>`::
(Required, object) Field you wish to search.

[[fuzzy-query-field-params]]
==== Parameters for `<field>`
`value`::
(Required, string) Term you wish to find in the provided `<field>`.

`fuzziness`::
(Optional, string) Maximum edit distance allowed for matching. See <<fuzziness>>
for valid values and more information.


`max_expansions`::
+
--
(Optional, integer) Maximum number of variations created. Defaults to `50`.

WARNING: Avoid using a high value in the `max_expansions` parameter, especially
if the `prefix_length` parameter value is `0`. High values in the
`max_expansions` parameter can cause poor performance due to the high number of
variations examined.
--

`prefix_length`::
(Optional, integer) Number of beginning characters left unchanged when creating
expansions. Defaults to `0`.

`transpositions`::
(Optional, boolean) Indicates whether edits include transpositions of two
adjacent characters (ab → ba). Defaults to `true`.

`rewrite`::
(Optional, string) Method used to rewrite the query. For valid values and more
information, see the <<query-dsl-multi-term-rewrite, `rewrite` parameter>>.