Updated October 25, 2026
· ~2 min read
The 2021 split was about licences. Elastic moved Elasticsearch off Apache 2.0; AWS forked it as OpenSearch. Both sides have moved since. In August 2024 Elastic added AGPLv3 as a licence option, making Elasticsearch open source again, and in September 2024 AWS moved OpenSearch to the OpenSearch Software Foundation under the Linux Foundation.
Five years on, they are different products with a shared ancestor. The choice is about features you need and how you want to run it, more than licensing.
Both engines do approximate nearest-neighbour search and hybrid (keyword plus vector) ranking, and both quantize vectors to cut memory. If vectors are the main reason you are looking, compare against S3 Vectors and pgvector first. A search engine earns its cost when you also need keyword relevance, filtering and aggregations at scale. We cover that choice in our vector storage comparison.
Question 1 of 2
Are you replacing a logging and observability stack, or building application search?
**Amazon OpenSearch Service:** AWS-native search and log analytics, IAM and VPC integration, and the lowest operating overhead if you are already on AWS. Serverless for spiky or small workloads. **Elastic Cloud:** you want Elastic's newest features, its observability and security products, and support from the company that builds Elasticsearch. Available through AWS Marketplace, so it can draw down AWS commitments. **Self-hosted on EKS:** large, steady clusters where a team that knows the engine can save meaningfully, or where data cannot leave your infrastructure. The most work.
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As of October 25, 2026. Provided as is, for general information, and accurate to the best of our knowledge on the date shown. Not legal, compliance, tax, financial or other professional advice. Prices, limits and vendor services change; check current vendor documentation before relying on anything here. Terms of use.