Apache Solr vs OpenSearch

Apache Solr: The original Lucene search server: battle-tested, Apache-governed, now with GPU-accelerated vectors. OpenSearch: Apache-licensed, foundation-governed fork of Elasticsearch for search, vectors and observability.

key differences

OpenSearch is built for larger datasets (Multi-PB) than Apache Solr (≤ 1 PB).
Only Apache Solr has joins, ttl / expiry.
Only OpenSearch has encryption at rest, streaming ingest.

choose apache-solr for

+Enterprise and intranet search
+Digital library and publishing search
+E-commerce catalog faceting
+Hybrid keyword and vector retrieval on existing Solr estates

best at · Search, Vector search, RAG

choose opensearch for

+Log analytics and observability
+Application and e-commerce search
+Vector and hybrid search for RAG on AWS
+Security event analytics

best at · Search, Vector search, RAG

Apache SolrThe original Lucene search server: battle-tested, Apache-governed, now with GPU-accelerated vectors.

OpenSearchApache-licensed, foundation-governed fork of Elasticsearch for search, vectors and observability.

overview

Primary model

Search Engine

Also supports

Document, Vector, Spatial

Document, Vector, Spatial, Time-Series

Type

Database engine

Status

Active

Developer

Apache Software Foundation

OpenSearch Software Foundation (Linux Foundation)

First release

2006

2021

Latest version

10.0.0 (Mar 3, 2026)

3.9.0 (Sep 29, 2026)

License

Open source (permissive)Apache License 2.0

Free tier

✓

popularity

WhichDB Score

39.8

56.6

Rank

#46

#18

GitHub stars

1.7K

13.9K

Stack Overflow questions

20.5K

1.1K

scale & guarantees

Comfortable data size

Large (≤ 1 PB)

Massive (Multi-PB)

Horizontal scaling

Native

Multi-region

Read replicas

ACID

Limited

Consistency

Eventual

Schema

Flexible

Architecture

Distributed, Client server

deployment

Self-hosted

✓

Vendor-managed cloud

—

Serverless

—

Embedded

—

Edge

—

Clouds

–

AWS, Oracle Cloud, Aiven, DigitalOcean

capabilities

Transactions

—

Joins

✓

—

Secondary indexes

✓

Full-text search

✓

Vector search

✓

Geospatial

✓

JSON

✓

Change data capture

—

Triggers

—

Stored procedures

—

Materialized views

—

TTL / expiry

✓

—

Pub/Sub

—

Columnar storage

—

In-memory

—

Durable persistence

✓

Compression

✓

Encryption at rest

—

✓

Role-based access

✓

Time travel

—

Branching

—

Online schema changes

✓

Streaming ingest

—

✓

Offline sync

—

Runs in WebAssembly

—

interfaces

Query languages

Lucene query syntax, JSON Request API, Streaming Expressions, SQL

Query DSL, PPL, SQL

Client languages

Java, Python, JavaScript, PHP, Ruby, .NET

Java, Python, JavaScript, Go, .NET, Ruby, PHP, Rust

Best for

Search, Vector search, RAG, Geo

Search, Vector search, RAG, Observability

Add more to this comparison Not sure either fits? Try smart match

Apache Solr vs OpenSearch: FAQ

What is the difference between Apache Solr and OpenSearch?

Apache Solr: The original Lucene search server: battle-tested, Apache-governed, now with GPU-accelerated vectors. OpenSearch: Apache-licensed, foundation-governed fork of Elasticsearch for search, vectors and observability. OpenSearch is built for larger datasets (Multi-PB) than Apache Solr (≤ 1 PB). Only Apache Solr has joins, ttl / expiry. Only OpenSearch has encryption at rest, streaming ingest.

When should I choose Apache Solr over OpenSearch?

Choose Apache Solr for enterprise and intranet search; digital library and publishing search; and E-commerce catalog faceting. Choose OpenSearch for log analytics and observability; application and e-commerce search; and vector and hybrid search for RAG on AWS.

Is Apache Solr or OpenSearch more popular?

OpenSearch ranks #18 on the WhichDB Score (56.6/100) and Apache Solr ranks #46 (39.8/100). Popularity is not fit: check the requirements that matter for your project.

Are Apache Solr and OpenSearch open source?

Yes. Apache Solr is open source. License: Apache License 2.0. Yes. OpenSearch is open source. License: Apache License 2.0.