It provides a distributed, multitenant-capable full-text search engine with an HTTP web interface and schema-free JSON documents.

[9] So he created "a solution built from the ground up to be distributed" and used a common interface, JSON over HTTP, suitable for programming languages other than Java as well.

[22][23] Other users of the Elasticsearch ecosystem, including Logz.io, CrateDB and Aiven, also committed to the need for a fork, leading to a discussion of how to coordinate the open source efforts.

[24][25][26] Due to potential trademark issues with using the name "Elasticsearch", AWS rebranded their fork as OpenSearch in April 2021.

[27][28] In August 2024 the GNU Affero General Public License was added as an option, making Elasticsearch free and open-source once again.

It supports facetting and percolating (a form of prospective search),[32] [33] which can be useful for notifying if new documents match for registered queries.

Elasticsearch supports real-time GET requests, which makes it suitable as a NoSQL datastore,[35] but it lacks distributed transactions.

[36] On 20 May 2019, Elastic made the core security features of the Elastic Stack available free of charge, including TLS for encrypted communications, file and native realm for creating and managing users, and role-based access control for controlling user access to cluster APIs and indexes.