GLOSSARY / DEFINITION
What is OpenSearch
OpenSearch is the open source search and analytics suite that exists because Elasticsearch relicensed away from open source. For enterprises carrying exposure from that change, understanding what OpenSearch is, and how it differs from the project it forked, is the first step in deciding whether it is the right open destination.
Definition
OpenSearch is an open source search and analytics suite created as a fork of Elasticsearch and its companion dashboard Kibana. Amazon Web Services led the fork in 2021, taking the last release published under the Apache 2.0 license and continuing it as a new project. OpenSearch is itself licensed under Apache 2.0, which means it remains open source as defined by the Open Source Initiative, with no competitive use restriction and no commercial license demand attached to running it in production. It provides full text search, log analytics, and observability features, and it ships with a dashboard component called OpenSearch Dashboards that corresponds to Kibana. For an enterprise, the headline fact is simple: OpenSearch is the open path that appeared when the project it descends from stopped being open.
Why OpenSearch exists
OpenSearch exists because of a relicense. In 2021 Elastic moved Elasticsearch and Kibana from the Apache 2.0 license to a dual model of the Server Side Public License and the Elastic License. The Server Side Public License is not approved as open source by the Open Source Initiative, and it carries conditions aimed at organizations that offer the software as a managed service. Cloud providers and enterprises that had built on the Apache 2.0 version faced a choice between accepting the new terms, buying a commercial license, or finding another path. AWS forked the last Apache 2.0 codebase and released it as OpenSearch, preserving an open option. This is the same pattern seen across the recent relicensing wave, where a move to source available terms is met by a community fork that keeps the open license alive. The same dynamic produced OpenTofu after the Terraform change and Valkey after the Redis change.
What it means for license risk
For an enterprise running a relicensed Elasticsearch, OpenSearch is usually the open destination on the table. Migrating to it can remove a Server Side Public License obligation or sidestep a commercial license demand, because OpenSearch carries neither. The decision is not automatic, though. OpenSearch began from the 2021 codebase and has diverged since, so the two projects share a heritage but have drifted apart in features, plugins, and clients. A migration has real engineering cost, and the right answer depends on which version you run, how deeply it is embedded, and what your roadmap needs. The disciplined approach is to map the full dependency tree, confirm exactly which Elasticsearch version and license state you are on, and size the move before committing. Whether a specific use of the older Apache 2.0 release or the relicensed version creates an obligation is a question for your own counsel.
Related reading
To understand the license that triggered the fork, see our definition of the Server Side Public License. To place OpenSearch in the wider pattern of forks born from relicensing, read what an open source fork is and how it works. For the parallel case in the database layer, see the Valkey definition. For the full set of terms, browse the rest of our open source license risk glossary.
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Questions buyers ask.
What is OpenSearch?
OpenSearch is an open source search and analytics suite created as a fork of Elasticsearch and Kibana. Amazon Web Services led the fork in 2021 after Elastic moved those projects from Apache 2.0 to the Server Side Public License and the Elastic License. OpenSearch is published under the Apache 2.0 license, so it remains open source as defined by the Open Source Initiative.
Why does OpenSearch exist?
It exists because Elasticsearch and Kibana relicensed away from open source in 2021. Organizations and cloud providers that relied on the Apache 2.0 version needed a path that stayed open. AWS forked the last Apache 2.0 release and continued it as OpenSearch, giving users an open destination rather than accepting the Server Side Public License or buying a commercial license.
Is OpenSearch the same as Elasticsearch?
They share a common ancestor but have diverged since 2021. OpenSearch began from the last Apache 2.0 codebase of Elasticsearch and Kibana and has developed its own features and roadmap. They are now distinct projects under different governance and different licenses, so they are compatible in many ways but not identical.
What does OpenSearch mean for license risk?
OpenSearch is the open path for an enterprise carrying exposure from the Elasticsearch relicense. Migrating to it can remove a Server Side Public License obligation or a commercial license demand. The decision still needs a mapped dependency tree and a sized migration, because the move has engineering cost and the two projects have drifted apart.
Is this legal advice?
No. This is commercial and licensing risk advisory, not legal advice. For interpretation of license terms in your specific use, engage your own counsel.