Azure AI Search vs OpenSearch
Azure AI Search: Microsoft's managed search service for full-text, vector, hybrid and agentic retrieval on Azure. OpenSearch: Apache-licensed, foundation-governed fork of Elasticsearch for search, vectors and observability.
key differences
- Licensing: Azure AI Search is proprietary (Proprietary (Azure service)); OpenSearch is open source (permissive) (Apache License 2.0).
- OpenSearch is built for larger datasets (Multi-PB) than Azure AI Search (≤ 1 PB).
- Transactions: Azure AI Search offers none ACID; OpenSearch offers limited.
- Only OpenSearch has compression, online schema changes, streaming ingest.
choose azure-ai-search for
- +Enterprise RAG over SharePoint and Blob content
- +Copilot and Foundry agent grounding
- +Site and catalog search on Azure
- +Hybrid semantic search for internal knowledge bases
best at · Search, Vector search, RAG
choose opensearch for
- +Log analytics and observability
- +Application and e-commerce search
- +Vector and hybrid search for RAG on AWS
- +Security event analytics
best at · Search, Vector search, RAG
Azure AI Search vs OpenSearch: FAQ
What is the difference between Azure AI Search and OpenSearch?
Azure AI Search: Microsoft's managed search service for full-text, vector, hybrid and agentic retrieval on Azure. OpenSearch: Apache-licensed, foundation-governed fork of Elasticsearch for search, vectors and observability. Licensing: Azure AI Search is proprietary (Proprietary (Azure service)); OpenSearch is open source (permissive) (Apache License 2.0). OpenSearch is built for larger datasets (Multi-PB) than Azure AI Search (≤ 1 PB). Transactions: Azure AI Search offers none ACID; OpenSearch offers limited.
When should I choose Azure AI Search over OpenSearch?
Choose Azure AI Search for enterprise RAG over SharePoint and Blob content; copilot and Foundry agent grounding; and site and catalog search on Azure. Choose OpenSearch for log analytics and observability; application and e-commerce search; and vector and hybrid search for RAG on AWS.
Is Azure AI Search or OpenSearch more popular?
OpenSearch ranks #18 on the WhichDB Score (56.6/100) and Azure AI Search ranks #70 (32.4/100). Popularity is not fit: check the requirements that matter for your project.
Are Azure AI Search and OpenSearch open source?
No. Azure AI Search is proprietary, closed-source software. Yes. OpenSearch is open source. License: Apache License 2.0.