head to head · open source
Milvus vs OpenSearch
Milvus has 46,563 GitHub stars, 4,325 forks, 1,405 open issues and last shipped yesterday. OpenSearch has 13,951 stars, 3,117 forks, 3,167 open issues and last shipped yesterday. Milvus leads on adoption by 234% (46,563 vs 13,951 stars). Milvus is written in Go under Apache-2.0; OpenSearch is written in Java under Apache-2.0. Milvus has attracted 9% as many forks as stars, OpenSearch 22%. OpenSearch was the more recently maintained of the two, and both are self-hostable with no licence fee.
Two open source projects, one decision. Both are free and self-hostable — the differences are community size, license terms, language stack and release pace.
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Side by side
| Milvus | OpenSearch | |
|---|---|---|
| GitHub stars | ★ 47K | ★ 14K |
| License | Apache-2.0 | Apache-2.0 |
| Written in | Go | Java |
| Last push | 2026-11-02 | 2026-11-02 |
| Forks | ⑂ 4.3K | ⑂ 3.1K |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick Milvus if
- You weight community size — 47K stars and counting
- You want the Apache-2.0 license terms
- Your stack matches Go
- You value the larger contributor base for long-term maintenance
pick OpenSearch if
- You want the OpenSearch feature set and don't need the biggest community
- You prefer the Apache-2.0 license terms
- Your stack matches Java
- You evaluated both and OpenSearch fits your workflow better
About Milvus
What is Milvus? 🐦 Milvus is a high performance vector database built for scale. It powers AI applications by efficiently organizing and searching vast amounts of unstructured data, such as text, images, and multi modal information. 🧑💻 Written in Go and C++, Milvus implements hardware acceleration for CPU/GPU to achieve best in class vector search performance. Thanks to its fully distributed and K8s native architecture, Milvus can scale horizontally, handle tens of thousands of search queries on billions of vectors, and keep data fresh with real time streaming updates. Milvus also supports Standalone mode for…
read the full Milvus overview →
About OpenSearch
Welcome! Project Resources Code of Conduct Security License Copyright Trademark Welcome! OpenSearch is an open source, enterprise grade search and observability suite that brings order to unstructured data at scale. Project Resources Project Website Downloads Documentation Need help? Try Forums or Slack Contributing to OpenSearch Maintainer Responsibilities Release Management Admin Responsibilities Testing Security Code of Conduct The project's Code of Conduct outlines our expectations for all participants in our community, based on the OpenSearch Code of Conduct. Please contact conduct@opensearch.foundation…
read the full OpenSearch overview →
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Frequently asked questions
Is Milvus or OpenSearch more popular?
Milvus has 46,563 GitHub stars and OpenSearch has 13,951. Milvus has the larger community by that measure.
Are Milvus and OpenSearch free?
Both are open source. Milvus is licensed under Apache-2.0 and OpenSearch under Apache-2.0. Neither carries a licence fee.
What is the difference between Milvus and OpenSearch?
Milvus is written in Go and OpenSearch in Java. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, Milvus or OpenSearch?
Choose Milvus if you want the larger community (46,563 stars) or its Apache-2.0 licence terms. Choose OpenSearch if its feature set, stack or Apache-2.0 licence fits better. Both are self-hostable.