Apache Solr vs Elasticsearch
A side-by-side comparison of two self-hosted search engines options — licensing, setup difficulty, resource needs, and what each one replaces.
Elasticsearch
Distributed search and analytics engine
| Feature | Apache Solr | Elasticsearch |
|---|---|---|
| Deploy effort | Under-an-hour setup | Under-an-hour setup |
| Health score | 81 · Excellent | 100 · Excellent |
| Category | Search Engines | Search Engines |
| License | Apache-2.0 | Elastic-2.0 |
| Language | Java | Java |
| Setup difficulty | Hard | Hard |
| Min. RAM | 1,024 MB | 2,048 MB |
| Deployment | docker, kubernetes, bare-metal | docker, kubernetes, bare-metal |
| GitHub stars | ★ 1,673 | ★ 77,967 |
| First released | 2006 | 2010 |
| Replaces | Elasticsearch, Algolia | Algolia, Splunk |
What are Apache Solr and Elasticsearch?
Apache Solr
Apache Solr is a highly reliable, scalable and fault-tolerant open-source search platform built on Apache Lucene. It powers full-text search, faceting and analytics for many large websites and applications.
- Lucene-powered full-text search
- Faceting and rich querying
- Distributed SolrCloud mode
- Extensive plugin ecosystem
Elasticsearch
Elasticsearch is a distributed, RESTful search and analytics engine capable of addressing a wide variety of use cases. It stores and indexes large volumes of data for fast full-text and structured search.
- Distributed full-text search
- Aggregations and analytics
- Horizontal scalability
- Rich query DSL
Apache Solr vs Elasticsearch: key differences
Both projects are written in Java. Licensing differs — Apache-2.0 for Apache Solr versus Elastic-2.0 for Elasticsearch. Apache Solr is the lighter option, starting around 1,024 MB of RAM against 2,048 MB for Elasticsearch. Apache Solr is the more established project (first released 2006), while Elasticsearch arrived in 2010. Elasticsearch has the considerably larger community, at 77,967 GitHub stars versus 1,673.
Why pick each one
Choose Apache Solr if…
- Mature and battle-tested
- Powerful faceting
Watch out for
- Configuration is complex
Choose Elasticsearch if…
- Extremely powerful and mature
- Huge ecosystem
Watch out for
- Resource intensive
- Complex to tune
Frequently asked questions
Is Apache Solr or Elasticsearch better?
Neither is universally better. Elasticsearch has the larger community; both share a hard setup difficulty, so the decision comes down to features and licensing.
Are Apache Solr and Elasticsearch free and open-source?
Yes. Apache Solr is licensed under Apache-2.0 and Elasticsearch under Elastic-2.0. Both can be self-hosted at no software cost.
Can I run Apache Solr and Elasticsearch with Docker?
Apache Solr: yes. Elasticsearch: yes.
Which is lighter on resources, Apache Solr or Elasticsearch?
Apache Solr has the smaller minimum footprint at 1,024 MB of RAM, compared to about 2,048 MB for Elasticsearch. Real-world usage depends on library size, user count, and enabled features.