Elasticsearch vs OpenSearch: Compared

Quick Verdict OpenSearch is the better choice for most self-hosters. It includes security, alerting, and anomaly detection for free — features that Elasticsearch partially gates behind paid tiers. The API is nearly identical (OpenSearch forked from Elasticsearch 7.10.2), so most tools work with both. Choose Elasticsearch only if you need the latest Elastic-specific features or tight integration with the official Elastic Stack. Overview OpenSearch is Amazon's fork of Elasticsearch, created in 2021 after Elastic changed Elasticsearch's license from Apache 2.0 to SSPL/Elastic License. In August 2024, Elastic relicensed Elasticsearch again — this time under AGPL v3 (alongside SSPL and Elastic License 2.0 as options). Both are distributed search and analytics engines based on Apache Lucene. Elasticsearch — AGPL v3 (also available under SSPL or Elastic License 2.0, your choice). The original. Created by Elastic. Most widely used search engine. Powers the ELK Stack (Elasticsearch, Logstash, K