head to head · open source
ClickHouse vs OpenSearch
ClickHouse has 49,952 GitHub stars, 8,970 forks, 7,547 open issues and last shipped today. OpenSearch has 13,727 stars, 2,957 forks, 3,167 open issues and last shipped today. ClickHouse leads on adoption by 264% (49,952 vs 13,727 stars). ClickHouse is written in C++ under Apache-2.0; OpenSearch is written in Java under Apache-2.0. ClickHouse has attracted 18% as many forks as stars, OpenSearch 22%. ClickHouse was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 1 topic tag (analytics), so they are genuine substitutes rather than adjacent tools.
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
| ClickHouse | OpenSearch | |
|---|---|---|
| GitHub stars | ★ 50K | ★ 14K |
| License | Apache-2.0 | Apache-2.0 |
| Written in | C++ | Java |
| Last push | 2026-09-18 | 2026-09-18 |
| Forks | ⑂ 9.0K | ⑂ 3.0K |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick ClickHouse if
- You weight community size — 50K stars and counting
- You want the Apache-2.0 license terms
- Your stack matches C++
- 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 ClickHouse
ClickHouse is an open source, column oriented database management system written in C++ that delivers real time analytical query performance on massive datasets. It operates within the broader data infrastructure ecosystem, serving as a high performance alternative to traditional row oriented databases for OLAP workloads.
read the full ClickHouse overview →
About OpenSearch
OpenSearch is an open source, distributed, and RESTful search engine, described in its README as an enterprise grade search and observability suite. It lives in the open source search and analytics ecosystem, is written in Java, and is licensed under Apache 2.0. The project states that it includes certain Apache licensed Elasticsearch code from Elasticsearch B.V., and that OpenSearch is a registered trademark of LF Projects, LLC.
read the full OpenSearch overview →
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Frequently asked questions
Is ClickHouse or OpenSearch more popular?
ClickHouse has 49,952 GitHub stars and OpenSearch has 13,727. ClickHouse has the larger community by that measure.
Are ClickHouse and OpenSearch free?
Both are open source. ClickHouse is licensed under Apache-2.0 and OpenSearch under Apache-2.0. Neither carries a licence fee.
What is the difference between ClickHouse and OpenSearch?
ClickHouse is written in C++ 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, ClickHouse or OpenSearch?
Choose ClickHouse if you want the larger community (49,952 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.