How to Sort by Relevance Score in Elasticsearch

In Elasticsearch, search results are sorted by relevance score by default using the _score field. To explicitly sort by relevance, include "sort": [{"_score": {"order": "desc"}}] in your query to order results from highest to lowest relevance score.

Syntax

The sort parameter in an Elasticsearch query controls the order of search results. To sort by relevance score, use the special field _score. The syntax looks like this:

• "sort": an array specifying sorting rules.
• {"_score": {"order": "desc"}}: sorts results by score in descending order (highest score first).

By default, Elasticsearch sorts by _score descending, so this is often implicit.

json

{
  "query": {
    "match": {
      "field_name": "search text"
    }
  },
  "sort": [
    {"_score": {"order": "desc"}}
  ]
}

Example

This example shows a search query that matches documents containing "elasticsearch" in the "content" field and sorts the results by relevance score descending.

json

{
  "query": {
    "match": {
      "content": "elasticsearch"
    }
  },
  "sort": [
    {"_score": {"order": "desc"}}
  ]
}

Output

[
  {
    "_id": "1",
    "_score": 3.5,
    "_source": {"content": "Elasticsearch tutorial"}
  },
  {
    "_id": "2",
    "_score": 2.1,
    "_source": {"content": "Introduction to Elasticsearch"}
  },
  {
    "_id": "3",
    "_score": 1.0,
    "_source": {"content": "Basic search guide"}
  }
]

Common Pitfalls

Many users expect sorting by _score to always happen, but if you add other sort fields without including _score, Elasticsearch sorts by those fields and ignores relevance score.

Also, sorting by _score ascending ("order": "asc") will show least relevant results first, which is usually not desired.

json

{
  "query": {
    "match": {"content": "elasticsearch"}
  },
  "sort": [
    {"date": {"order": "desc"}}
  ]
}

// This sorts by date, ignoring relevance score.

{
  "query": {
    "match": {"content": "elasticsearch"}
  },
  "sort": [
    {"_score": {"order": "desc"}},
    {"date": {"order": "desc"}}
  ]
}

// This sorts first by relevance score, then by date if scores tie.

Quick Reference

Concept	Description	Example
_score	Field representing relevance score	{"sort": [{"_score": {"order": "desc"}}]}
Default sorting	Elasticsearch sorts by _score descending if no sort specified	No sort parameter needed
Sort by other fields	Overrides _score sorting, relevance ignored	{"sort": [{"date": {"order": "desc"}}]}
Combine sorting	Sort by _score then by another field	{"sort": [{"_score": {"order": "desc"}}, {"date": {"order": "desc"}}]}

Key Takeaways

Elasticsearch sorts search results by relevance score (_score) descending by default.

Use the sort parameter with _score and order desc to explicitly sort by relevance.

Adding other sort fields without _score disables sorting by relevance.

Sorting _score ascending shows least relevant results first, usually unwanted.

Combine _score sorting with other fields by listing _score first in the sort array.