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QLever vs OpenLink Virtuoso

QLever: Fast open-source SPARQL engine that serves all of Wikidata or OpenStreetMap from one machine. OpenLink Virtuoso: Hybrid SQL/RDF engine that runs many of the largest public SPARQL endpoints.

key differences

  • Licensing: QLever is open source (permissive) (Apache License 2.0); OpenLink Virtuoso is open source (copyleft) (GPL-2.0 (Open Source Edition); commercial edition proprietary).
  • Horizontal scaling is none in QLever and addon in OpenLink Virtuoso.
  • Transactions: QLever offers limited ACID; OpenLink Virtuoso offers full.
  • Only OpenLink Virtuoso has transactions, joins, secondary indexes, triggers, stored procedures.

choose qlever for

  • +Public SPARQL endpoints for Wikidata, OSM, UniProt
  • +Large read-mostly knowledge graphs
  • +Research on big RDF datasets
  • +Replacing aging Blazegraph deployments

best at · Knowledge graph, OLAP, Scientific

choose virtuoso for

  • +Public Linked Open Data endpoints
  • +Large RDF datasets in life sciences
  • +Hybrid SQL plus RDF data integration
  • +Semantic web publishing

best at · Knowledge graph, OLAP, Content

QLeverFast open-source SPARQL engine that serves all of Wikidata or OpenStreetMap from one machine.
OpenLink VirtuosoHybrid SQL/RDF engine that runs many of the largest public SPARQL endpoints.
overview
Primary model
RDF / Triple Store
RDF / Triple Store
Also supports
–
Relational, XML
Type
Database engine
Database engine
Status
Active
Active
Developer
University of Freiburg (Chair of Algorithms and Data Structures)
OpenLink Software
First release
2017
1998
Latest version
0.6.0 (Aug 13, 2026)
7.2.17 (May 7, 2026)
License
Open source (permissive)Apache License 2.0
Open source (copyleft)GPL-2.0 (Open Source Edition); commercial edition proprietary
Free tier
✓
✓
popularity
WhichDB Score
17.9
19.5
Rank
#186
#167
GitHub stars
931
976
Stack Overflow questions
3
533
scale & guarantees
Comfortable data size
Large (≤ 1 PB)
Large (≤ 1 PB)
Horizontal scaling
None
Addon
Multi-region
None
None
ACID
Limited
Full
Consistency
Strong
Strong
Schema
Schemaless
Flexible
Architecture
Single node, Client server
Single node, Client server, Distributed
deployment
Self-hosted
✓
✓
Vendor-managed cloud
—
—
Serverless
—
—
Embedded
—
—
Edge
—
—
Clouds
–
AWS
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
SPARQL
SPARQL, SQL, SPASQL
Client languages
Any SPARQL client
ODBC, JDBC, Python, PHP, Jena/RDF4J adapters
Best for
Knowledge graph, OLAP, Scientific, Geo
Knowledge graph, OLAP, Content, Metadata
Add more to this comparisonNot sure either fits? Try smart match

QLever vs OpenLink Virtuoso: FAQ

What is the difference between QLever and OpenLink Virtuoso?

QLever: Fast open-source SPARQL engine that serves all of Wikidata or OpenStreetMap from one machine. OpenLink Virtuoso: Hybrid SQL/RDF engine that runs many of the largest public SPARQL endpoints. Licensing: QLever is open source (permissive) (Apache License 2.0); OpenLink Virtuoso is open source (copyleft) (GPL-2.0 (Open Source Edition); commercial edition proprietary). Horizontal scaling is none in QLever and addon in OpenLink Virtuoso. Transactions: QLever offers limited ACID; OpenLink Virtuoso offers full.

When should I choose QLever over OpenLink Virtuoso?

Choose QLever for public SPARQL endpoints for Wikidata, OSM, UniProt; large read-mostly knowledge graphs; and research on big RDF datasets. Choose OpenLink Virtuoso for public Linked Open Data endpoints, large RDF datasets in life sciences and hybrid SQL plus RDF data integration.

Is QLever or OpenLink Virtuoso more popular?

OpenLink Virtuoso ranks #167 on the WhichDB Score (19.5/100) and QLever ranks #186 (17.9/100). Popularity is not fit: check the requirements that matter for your project.

Are QLever and OpenLink Virtuoso open source?

Yes. QLever is open source. License: Apache License 2.0. Yes. OpenLink Virtuoso is open source. License: GPL-2.0 (Open Source Edition); commercial edition proprietary.