Adequately debugging and validating RDF documents is a Herculean task to perform manually. Thankfully, there are numerous tools for checking RDF documents to help you along the way, each with its own error-checking functionalities. Some are available online for convenience; some are command line tools designed for larger jobs. In any case, we now provide a comprehensive list of such tools—a list that is sure to grow.
Table of Contents
Online Validators
Parsing and Syntax
W3C RDF/XML Validation Service: Perhaps the most popular tool for validation, this service accepts an RDF/XML document as input, ensures that the document is syntactically valid (can be parsed into tripes according with the RDF/XML specification) and will subsequently display triples and/or a simple graphical representation of the data.
W3C Markup Validation Service: The W3C's HTML validator checks syntactic correctness for web pages that contain embedded RDFa markup, provided the XHTML+RDFa doctype is used. The validator however only checks validity according to the RDFa DTD; this means that many kinds of errors, such as undeclared namespace prefixes, or invalid datatyped literals, are not detected.
Accessibility/Dereferencing
Vapour, a Linked Data Validator: Checks the dereferencability of a given URI and provides feedback on content negotiation/redirect codes and can determine whether the given URI is an information resource or a non-information resource. The system optionally checks whether the resolved document contains data about the dereferenced URI and has special features for performing checks on the dereferencability of vocabulary terms and namespaces.
URI Debugger: Displays the request and response header for accessing a given URI; the system further allows for specifying custom User-Agent and Accept-Header fields. The content of the request is then displayed, with all URIs displayed with a link to recursively debug.
RDF Triple-Checker: Checks the dereferenceability of namespaces associated with class and property terms used in a document. Checks to see if the specific class or property URI is defined in the namespace document, and if the namespace corresponds with a well-known prefix.
Vocabulary-specific Validators
QDOS FOAF Validator: Performs an in-depth check for common authoring errors in FOAF files (personal profiles that use the Friend of a Friend vocabulary). Only the common RDF/XML syntax is supported; others such as Turtle, N3 and RDFa are not supported.
Ontologies
Pellet OWL Reasoner Validator: Checks the species of an OWL ontology, and, optionally, checks the consistency of an ontology and checks for unsatisfiable concepts. Please note that this system can be quite buggy.
General Validators
RDF:ALERTS: A general purpose validator which checks for syntax errors, undefined classes or properties, inconsistencies, bogus inverse-functional property values, atypical use of core vocabularies, datatype errors and more.
Other Resources
Command-line Validators
Eyeball: A validator integrated with Jena which checks for a plethora of problems in RDF data, including use of undefined properties or classes, poorly formed namespaces, problematic prefix declarations, some simple literal validation (not including validation of lexical values) and other optional heuristic checks.
The Validating RDF Parser (VRP): A parser which syntactically validates data, including datatypes, and can check that it satisfies RDFS constraints. Available for download under the RDFSuite license.