Milvus vs Amazon OpenSearch Service

Milvus8.6Visit Amazon OpenSearch Service8.2Visit

Higher score Milvus #4 in Ai Databases 8.6/10 Free plan Free plan✓ 2 of 3 features Visit Milvus

vs

Amazon OpenSearch Service #8 in Ai Databases 8.2/10 Paid ✓ 2 of 3 features Visit AWS

• Milvus fits best

  Developers wanting open-source vector search

• Amazon OpenSearch Service fits best

  AWS users building managed vector search and RAG

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Side by side

Feature	Milvus 8.6/10 Visit ↗	Amazon OpenSearch Service 8.2/10 Visit ↗
At a glance
Editor score	8.6	8.2
Ranking	#4 in Ai Databases	#8 in Ai Databases
Best for	Developers wanting open-source vector search	AWS users building managed vector search and RAG
Pricing model	Free	Paid
Starting price	Free plan	Not checked yet
Free plan	✓ (best)	—
Free trial	—	—
Deployment	Cloud, Self-hosted	Cloud
Support	Community, Docs	Live chat, Tickets, Docs
Integrations	8 integrations	13 integrations
Built for	Solo, Small business, Mid-market, Enterprise	Small business, Mid-market, Enterprise
Features Milvus 2/3 · Amazon OpenSearch Service 2/3
Metadata filtering	✓	✓
Hybrid search	✓	✓
Managed backups	Not checked yet	Not checked yet
Specs
Deployment	Not checked yet	Not checked yet
Index types	HNSW, IVF, FLAT, DiskANN, SCANN	Not checked yet
Max vector dimensions	Not checked yet	16000
Our review
Pros	Supports hybrid dense-sparse search, BM25, and metadata filtering Offers HNSW, IVF, FLAT, DiskANN, and SCANN index types Runs locally, as a standalone server, or on distributed Kubernetes	Combines vector and lexical search, with metadata filtering. Offers serverless collections with automatic scaling and scale-to-zero. Connects with AWS services including S3, Kinesis, and Bedrock.
Cons	Self-hosted deployment requires operating the database infrastructure Support channels listed are community and documentation Managed cloud is a separate Zilliz Cloud service	Paid, usage-based pricing varies by deployment model and Region. Requires AWS ecosystem fit for its broadest integration value. Managed domains require choices for compute and storage configuration.
Our verdict	Milvus is an open-source vector database for developers and organizations building semantic search, retrieval-augmented generation, recommendations, image search, and other AI applications. It stores, indexes, and searches dense, sparse,… Read the review →	For teams building search, analytics, observability, or AI applications on AWS, Amazon OpenSearch Service provides managed OpenSearch domains and serverless collections. Its vector features support k-nearest-neighbor retrieval, semantic… Read the review →

Strengths and trade-offs

• Milvus — where it wins

  • Supports hybrid dense-sparse search, BM25, and metadata filtering
  • Offers HNSW, IVF, FLAT, DiskANN, and SCANN index types
  • Runs locally, as a standalone server, or on distributed Kubernetes

  Where it doesn't

  • Self-hosted deployment requires operating the database infrastructure
  • Support channels listed are community and documentation
  • Managed cloud is a separate Zilliz Cloud service

• Amazon OpenSearch Service — where it wins

  • Combines vector and lexical search, with metadata filtering.
  • Offers serverless collections with automatic scaling and scale-to-zero.
  • Connects with AWS services including S3, Kinesis, and Bedrock.

  Where it doesn't

  • Paid, usage-based pricing varies by deployment model and Region.
  • Requires AWS ecosystem fit for its broadest integration value.
  • Managed domains require choices for compute and storage configuration.

• Milvus8.6/10 · Free plan

  A flexible vector search foundation for teams that want open-source or self-hosted deployment.

  Visit MilvusFull verdict →
• Amazon OpenSearch Service8.2/10 · Paid

  A managed AWS option for teams combining vector retrieval with lexical search.

  Visit AWSFull verdict →