OpenSearch vs Elasticsearch: Which Search Engine?
OpenSearch is the Apache-2.0 fork of Elasticsearch led by AWS and the community; Elasticsearch is the original engine under Elastic licensing.
OpenSearch forked from Elasticsearch 7.10 after the license change, offering a fully open (Apache-2.0) search and analytics engine with its own dashboards and feature roadmap. Elasticsearch continues under Elastic with the SSPL/Elastic License (and again AGPL), shipping advanced features and tight commercial integration. OpenSearch wins on permissive licensing and AWS integration; Elasticsearch wins on the most advanced features and the original ecosystem.
| OpenSearch | Elasticsearch | |
|---|---|---|
| License | Apache-2.0 | Elastic / AGPL / SSPL |
| Origin | Fork of ES 7.10 | Original |
| Dashboards | OpenSearch Dashboards | Kibana |
| Cloud fit | AWS-native | Elastic Cloud |
| Best for | Open license, AWS | Latest features, original |
Use case and licensing
OpenSearch suits teams that need a fully permissive license or run on AWS-managed OpenSearch Service. Elasticsearch suits teams wanting the latest features, ML, and the original Elastic ecosystem and commercial support.
Ops and CI fit
The two have diverged over time but remain broadly similar to operate; client and API compatibility varies by version. Both are integration-tested in CI against ephemeral clusters, where faster managed runners speed image pulls and index tests.
Decide with your own numbers, not a feature table
Feature comparisons age badly and rarely decide anything, because both tools in a mature category can do the job. What differs is how each behaves on your repository, and that takes one afternoon to measure.
# time a cold install with each candidate, cache cleared
hyperfine --prepare "rm -rf node_modules" --warmup 1 \
"<tool-a> install" "<tool-b> install"
# and the thing CI actually pays for: a cold run with no local cache
docker run --rm -v "$(pwd):/w" -w /w node:22 sh -c "<tool> install"What actually changes when you switch
- Lockfile format. A switch is a one-way door for anyone still on the old tool until everyone migrates, so plan it as a single coordinated change.
- Resolution strictness. Tools differ on whether an undeclared transitive import works, and the stricter one will surface latent bugs as new failures.
- CI cache configuration. The cache path and key differ per tool; carrying over the old ones silently disables caching.
- Everyone on the team and every runner must move together. Pin the version so they cannot drift.
The verdict
Need a permissive Apache-2.0 license or AWS-managed search: OpenSearch. Want the latest features and the original ecosystem: Elasticsearch. License and cloud strategy usually decide it.