elasticsearch/docs/reference/query-languages/query-dsl-fuzzy-query.md

navigation_title	mapped_pages
Fuzzy	https://www.elastic.co/guide/en/elasticsearch/reference/current/query-dsl-fuzzy-query.html

Fuzzy query [query-dsl-fuzzy-query]

Returns documents that contain terms similar to the search term, as measured by a 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 (box → fox)
• Removing a character (black → lack)
• Inserting a character (sic → sick)
• Transposing two adjacent characters (act → cat)

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.

Example requests [fuzzy-query-ex-request]

Simple example [fuzzy-query-ex-simple]

GET /_search
{
  "query": {
    "fuzzy": {
      "user.id": {
        "value": "ki"
      }
    }
  }
}

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

GET /_search
{
  "query": {
    "fuzzy": {
      "user.id": {
        "value": "ki",
        "fuzziness": "AUTO",
        "max_expansions": 50,
        "prefix_length": 0,
        "transpositions": true,
        "rewrite": "constant_score_blended"
      }
    }
  }
}

Top-level parameters for fuzzy [fuzzy-query-top-level-params]

<field>

(Required, object) Field you wish to search.

Parameters for <field> [fuzzy-query-field-params]

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 rewrite parameter.

Notes [fuzzy-query-notes]

Fuzzy queries will not be executed if search.allow_expensive_queries is set to false.