Skip to main content
Meilisearch uses bucket sort to rank search results. This algorithm distributes documents into buckets based on ranking rules, then recursively sorts within each bucket using subsequent rules.

​
How bucket sort works in Meilisearch

When you search, Meilisearch doesn’t score documents with a single number. Instead, it applies ranking rules sequentially, sorting documents into buckets at each step.

​
Example: Searching for “Badman dark knight returns”

Step 1: Apply the words rule The first ranking rule (words) sorts documents by how many query words they contain:
BucketMatchesDocuments
1All 4 words”Batman: The Dark Knight Returns”
23 words”Batman: The Dark Knight”
32 words…
41 word”Angel and the Badman”
Step 2: Apply the typo rule within buckets If a bucket contains multiple documents, the next rule (typo) breaks ties. For example, in the 1-word bucket where “Badman” appears:
BucketTyposDocuments
4.10 typosDocuments containing “Badman” exactly
4.21 typoDocuments corrected “Badman” → “Batman”
This continues recursively until all buckets contain single documents or all ranking rules are exhausted.

​
Why bucket sort?

Bucket sort offers several advantages for search ranking:
  1. Flexibility: Different sorting algorithms can be applied within individual buckets
  2. Configurable priority: You control which criteria matter most by reordering rules
  3. Efficient tie-breaking: Only documents that tie on one rule need evaluation by the next

​
Best and worst cases

CaseConditionComplexity
BestDocuments spread evenly across bucketsO(n+k) where n=documents, k=buckets
WorstAll documents in one bucketDepends on the sorting algorithm used

​
Default ranking rules

Meilisearch applies these rules in order:
  1. words: Documents containing more query words rank higher
  2. typo: Documents with fewer typos rank higher
  3. proximity: Documents where query words appear closer together rank higher
  4. attributeRank: Documents matching in more important attributes rank higher
  5. sort: User-defined sort order (if specified)
  6. wordPosition: Documents with matches closer to the beginning of an attribute rank higher
  7. exactness: Documents with exact matches rank higher

​
Customizing ranking rules

You can reorder, add, or remove ranking rules: 
curl -X PUT "${MEILISEARCH_URL}/indexes/movies/settings/ranking-rules" \
  -H "Authorization: Bearer ${MEILISEARCH_API_KEY}" \
  -H "Content-Type: application/json" \
  --data-binary '[
    "words",
    "typo",
    "proximity",
    "attributeRank",
    "sort",
    "wordPosition",
    "exactness",
    "release_date:desc"
  ]'
Adding release_date:desc as a custom rule means newer movies rank higher when all other factors are equal.