Combining vector (semantic) similarity with traditional keyword search (BM25) — vector search finds meaning-similar docs, keyword search catches exact-match queries the embeddings miss.
retrieval
Hybrid Search
Related terms
Tools that implement Hybrid Search
WE
Weaviate
RAG · Hosted vector DB (not an LLM)
8.4
Open-source vector DB with hybrid search and modules.
Freemium· Free: $0 · Flex: $45 · Premium: $400self-hosted RAGhybrid search
VE
Vespa
RAG · Hosted search engine (not an LLM)
8.2
Yahoo's open-source search engine with vector + sparse retrieval.
Freemium· Free open-source; Vespa Cloud paidlarge-scale searchranking
EV
Elasticsearch Vector Search
RAG · BYO embeddings (OpenAI, Cohere, Hugging Face, Mistral, Bedrock, Vertex, Azure) plus Elastic's built-in ELSER sparse model and E5 dense model
8.7
Hybrid vector + keyword search in the enterprise-grade Elasticsearch engine
Freemium· Resource based pricing: Pay as you go (monthly) or prepaid · Usage based pricing: Pay as you go (monthly) or prepaid · License based pricing: ?RAG chatbot over enterprise docsHybrid semantic + keyword product search