RDFox

RDFox is a main-memory data store for centralized RDF graphs queried with SPARQL 1.1. It supports rules and ontological axioms using Datalog, OWL 2, and SWRL, and updates rule consequences as data changes. The maker says it can process 2–3 million new-fact inferences per second. RDFox also supports OWL 2 RL and SHACL, and offers a native API for Java applications and a REST API for standalone-server operation. Import and export formats include CSV, JSON, N-Triples, Turtle, TriG, and OWL 2 Functional-Style Syntax. It can replicate knowledge and data changes across servers for service continuity during an outage. Deployments are described for cloud, on-premises, on-device, and edge environments; the software runs on Linux, macOS, and Windows. A free 30-day evaluation license is limited to evaluation and non-commercial use. Commercial licensing requires a key and pricing is on request.

RDFox brings RDF storage, SPARQL querying, and incremental reasoning together, with several deployment options. Commercial use requires a license key, and its price is available on request.

RDFox suits teams building or operating RDF knowledge graphs that need SPARQL querying and rule-based reasoning. It may also suit organizations deploying across cloud, on-premises, on-device, or edge environments.

Overview

RDFox is a centralized, main-memory store for RDF graphs, combining SPARQL 1.1 queries with rule-based reasoning. It is best suited to teams building knowledge-graph applications where new data needs to update inferred knowledge quickly. Its strong point is real-time incremental reasoning; its chief trade-off is that commercial use requires a license key and custom pricing.

Key features

RDFox brings RDF storage, SPARQL querying and semantic reasoning into one system. It supports Datalog, OWL 2, SWRL and SHACL, covering both inference from graph data and validation needs. That makes it a more appropriate choice for applications that depend on rules and ontologies than for teams that only need a graph store and query language.

When data changes, RDFox updates rule consequences in real time and can process 2–3 million new-fact inferences per second. That capacity is compelling for systems where fresh facts should quickly affect the knowledge model, though the stated rate alone does not establish performance for a particular workload.

Integration options include a native API for Java applications and a RESTful API for standalone-server operation. RDFox imports and exports formats such as CSV, JSON, N-Triples, Turtle, TriG and OWL 2 Functional-Style Syntax. It can also replicate knowledge and data changes across servers, which supports continuity if one server becomes unavailable.

Deployment spans cloud, on-premises, on-device and edge environments, with Linux, macOS and Windows support. Docker images are designed to run without superuser capabilities. Security features include encryption at rest and mutual-TLS client-certificate authentication; OpenID Connect single sign-on supports external identity systems such as Microsoft Entra. AWS Marketplace deployment adds pay-as-you-go access and connectors for SQL, CSV, XML, JSON, REST and unstructured data.

Pricing

The RDFox free evaluation license costs nothing for a 30-day trial. It is limited to evaluation and non-commercial use, so it is not a continuing free tier for production or paid work.

The commercial license requires a license key and uses custom pricing. This is the relevant route for production use, but teams should account for the need to contact Oxford Semantic Technologies rather than choosing from a stated price. A Community Slack channel and a stated aim to respond to contact messages within two working days provide support routes.

Platforms

RDFox runs on Linux, macOS and Windows and can be deployed on cloud, on-premises, on-device or at the edge. API, web and self-hosted options suit teams integrating the store into applications or operating it themselves; the range does not make the product a general-purpose desktop graph editor.

Who it's for

RDFox is a strong fit for developers and data teams that need RDF graphs, standards-based querying and inference in an application, particularly when consequences must update as source data changes. Its multiple deployment options and APIs also suit organizations choosing between centralized infrastructure and edge or device deployments. It is less suitable for casual graph exploration or buyers who need a commercial price they can compare before contacting the vendor.

Pros and cons

• Pros: Incremental reasoning updates consequences in real time, with a stated throughput of 2–3 million new-fact inferences per second.
• Pros: Support for SPARQL 1.1, Datalog, OWL 2, SWRL and SHACL serves applications that need both graph querying and semantic reasoning.
• Pros: Java and REST APIs, multiple operating systems and deployment models give teams options for integrating and running the store.
• Cons: The free license lasts only 30 days and is restricted to non-commercial evaluation.
• Cons: Commercial licensing requires a key and custom pricing, which makes upfront cost comparison difficult.

Alternatives

For a broader survey, browse Knowledge Graph Software or RDF Databases.

Choose HASH if a lifetime-free plan with 10GB file storage and capped manual scraping jobs better fits the work. Neo4j is another freemium graph database option, with its free AuraDB plan managed and self-hosted platform support.

AllegroGraph offers a free tier capped at 5 million triples, which may suit a smaller graph before an enterprise quote. GraphDB has a free single-core license, making it an alternative when that constraint is acceptable.

LinkedDataHub is a free, Apache 2.0, self-hosted option. Mendix offers a free plan limited to one deployment environment per application. For ontology work, Protégé is a free and open-source OWL 2 tool; RDF Studio is a free semantic data workspace.

Verdict

Choose RDFox if your application needs RDF storage and SPARQL alongside fast, incremental reasoning, with the freedom to deploy across servers, cloud or edge environments. Its combination of standards, APIs and live consequence updates is the main reason to choose it. Look elsewhere if commercial pricing transparency or a free production plan is essential.