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Head-to-head · Knowledge Graph Software

AllegroGraph vs Ontop

  • Updated Oct 2026
  • Both researched from official sources
  • 5 checks side by side
Higher score AllegroGraph #6 in Knowledge Graph Software 8.6/10 Free plan Free plan✓ 4 of 4 features Visit AllegroGraph
Ontop #15 in Knowledge Graph Software 7.7/10 Open source ✓ 3 of 4 features Visit Ontop

AllegroGraph leads on 0 checks, Ontop on 0, and 5 are even. Who comes out ahead on the 5 yes/no, price and count checks where we have data for both products. The editor score weighs everything else too.

Our verdict

  • Highest scoreAllegroGraph · 8.6/10
  • Free planonly AllegroGraph
  • Most featuresAllegroGraph · 4 of 4

AllegroGraph scores higher on our rubric for knowledge graph software: 8.6 against 7.7 out of 10; our editors rank them #6 and #15.

AllegroGraph is the better fit for enterprise semantic graphs with advanced operations. Ontop is the better fit for virtual knowledge graphs over relational databases.

  • AllegroGraph fits best

    Enterprise semantic graphs with advanced operations

  • Ontop fits best

    Virtual knowledge graphs over relational databases

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Side by side

Feature AllegroGraph 8.6/10 Visit ↗ Ontop 7.7/10 Visit ↗
At a glance
Editor score 8.6 7.7
Ranking #6 in Knowledge Graph Software #15 in Knowledge Graph Software
Best for Enterprise semantic graphs with advanced operations Virtual knowledge graphs over relational databases
Pricing model Free plan + paid Free
Starting price — Open source
Free plan ✓ (best) Not checked yet
Free trial — —
Deployment Cloud, Self-hosted Self-hosted
Platforms Web, Windows, macOS, Linux Windows, macOS, Linux
Support Email, Docs Community, Docs
Integrations 9 integrations 20 integrations
Built for Mid-market, Enterprise Small business, Mid-market, Enterprise
Features AllegroGraph 4/4 · Ontop 3/4
Ontology modeling ✓ ✓
Semantic reasoning ✓ ✓
RDF/SPARQL support ✓ ✓
Graph visualization ✓ (best) Not checked yet
Specs
Import formats JSON-LD, N-Quads, N-Triples, Extended N-Quads, RDF/XML, TriG, TriX, Turtle, JSON, JSONLines, CSV RDF/XML, Turtle, N-Triples, N-Quads, TriG, JSON-LD, R2RML, Ontop mapping format
Deployment Both Both
Query languages SPARQL, Prolog SPARQL
Our review
Pros
  • Free plan supports up to 5 million triples without expiration
  • Combines SPARQL, Prolog, RDF storage, and semantic reasoning
  • Supports sharding, federation, replication, and cloud or on-premises deployment
  • Translates SPARQL queries into SQL for existing relational sources
  • Supports RDFS, OWL 2 QL, R2RML, and native Ontop mappings
  • Connects with databases including PostgreSQL, Snowflake, and BigQuery
Cons
  • Enterprise pricing is quote-based
  • Advanced capabilities may exceed the needs of smaller graph projects
  • The Free plan is limited to 5 million triples
  • Requires relational databases and mapping work as its foundation
  • Its open-source model requires teams to manage deployment themselves
  • Its focus is semantic querying rather than a broad application suite
Our verdict

AllegroGraph is a semantic graph database for organizations building knowledge graphs, data fabrics, and AI applications. It stores RDF, graph, vector, document, and temporal data, with support for SPARQL, OWL reasoning, SHACL, rules, and…

Read the review →

Ontop is an open-source virtual knowledge graph system for teams that need to expose relational database content as RDF without moving the underlying data. It translates SPARQL queries over the virtual graph into SQL executed by relational…

Read the review →
  1. AllegroGraphKnowledge Graph Software 8.6Free plan
  2. OntopKnowledge Graph Software 7.7Open source

Strengths and trade-offs

  • AllegroGraph — where it wins

    • Free plan supports up to 5 million triples without expiration
    • Combines SPARQL, Prolog, RDF storage, and semantic reasoning
    • Supports sharding, federation, replication, and cloud or on-premises deployment

    Where it doesn't

    • Enterprise pricing is quote-based
    • Advanced capabilities may exceed the needs of smaller graph projects
    • The Free plan is limited to 5 million triples

  • Ontop — where it wins

    • Translates SPARQL queries into SQL for existing relational sources
    • Supports RDFS, OWL 2 QL, R2RML, and native Ontop mappings
    • Connects with databases including PostgreSQL, Snowflake, and BigQuery

    Where it doesn't

    • Requires relational databases and mapping work as its foundation
    • Its open-source model requires teams to manage deployment themselves
    • Its focus is semantic querying rather than a broad application suite

More comparisons

All knowledge graph software comparisons → · Full ranking →

Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026

Last updated · How we research and update