Glossary

BM25

The standard relevance-ranking function for full-text search.

1 min read·4 sections
Open the interactive version → diagrams, practice & more

Definition

The standard relevance-ranking function for full-text search.

How it works

Scores documents by term frequency + rarity; what Elasticsearch uses to order results.

Common questions

What is BM25?

The standard relevance-ranking function for full-text search.

How does BM25 work?

Scores documents by term frequency + rarity; what Elasticsearch uses to order results.

What is BM25 used for in system design?

Scores documents by term frequency + rarity; what Elasticsearch uses to order results.

Part of Glossary on SystemLore — system design explained with 148 deep topics, interactive diagrams, and a build-it-yourself game. Build this one →