isSemantic.net

Free plan Web

What isSemantic.net is

isSemantic.net is a free web tool for validating, generating, visualizing and converting structured data. Its validator checks JSON-LD, RDFa and Microdata against Schema.org, Google Search, Facebook Open Graph, Twitter Cards, Facebook App Links and HTML outline semantics. Markup that uses vocabularies outside Schema.org is identified separately rather than validated. The generator builds or edits markup from examples for Google Search, Schema.org, Open Graph and Twitter Cards; users can add Schema.org properties or import a snippet. Google and Schema.org output is JSON-LD, while Open Graph and Twitter Cards output is RDFa. For RDF, a graph view is accompanied by a triples table and a hierarchical view. Supported formats include JSON-LD, Microdata, N-Quads, N-Triples, N3, RDFa, RDF/XML, TriG and Turtle, with provisional RDF-star support. The converter takes a URL or snippet, can identify its format and converts between RDF serializations. Its terms limit use to private, non-commercial purposes. The service says it does not store or redistribute accessed public structured data, but it uses cookies and stores IP addresses for core features and legal claims.

Who it suits

It suits people who need to inspect, create or convert structured data in a browser. Its private, non-commercial use restriction may not suit commercial workflows.

What it does well

Checks JSON-LD, RDFa and Microdata against listed standards.
Generates JSON-LD and RDFa markup from examples.
Shows RDF as a graph, table and hierarchy.
Converts RDF from a URL or code snippet.
Free plan; runs on the web.

What to know first

Terms restrict use to private, non-commercial purposes.
Non-Schema.org vocabularies are not validated.
Search-result appearance is not guaranteed.
Cookies and IP address storage are disclosed.

Getting started

Open isSemantic.net in a web browser.
Choose the validator, generator, RDF visualizer or converter.
Paste markup or a snippet, or provide a web address for conversion.
For generation, start from an available example and add Schema.org properties or import a snippet as needed.

Verdict

isSemantic.net brings several structured-data tasks together in one web tool, including validation, markup generation and RDF conversion. Check its usage restriction and validation scope against your needs before relying on it.

Questions

Is isSemantic.net free?

Yes. It has a free plan.

Which markup formats can the validator accept?

It accepts JSON-LD, RDFa and Microdata. Markup using vocabularies other than Schema.org is shown separately rather than validated.

What formats does the generator produce?

Google and Schema.org markup is provided as JSON-LD. Open Graph and Twitter Cards markup is provided as RDFa.

Can I use isSemantic.net for commercial work?

The terms restrict use to private, non-commercial purposes.

Does the service store structured data it accesses?

The terms say it accesses third-party websites only to analyze publicly available structured data and does not store or redistribute that data. The consent notice says IP addresses are stored as needed for core features and legal claims.

Does passing validation mean markup will appear in search results?

No. The validator does not guarantee that correctly marked-up data will appear in search results.

Facts from isSemantic.net's own pages

Data handling: The terms say the service accesses third-party websites only to analyze publicly available structured data and does not store or redistribute that accessed data. · issemantic.net, 4 Oct 2026
Generated formats: The generator outputs JSON-LD for Google and Schema.org markup and RDFa for Open Graph and Twitter Cards. · issemantic.net, 8 Oct 2026
Generator: The generator creates and edits markup from Google Search, Schema.org, Open Graph and Twitter Cards examples, and supports custom Schema.org snippets. · issemantic.net, 8 Oct 2026
Generator formats: Generated Google and Schema.org markup is provided as JSON-LD, while Open Graph and Twitter Cards markup is provided as RDFa. · issemantic.net, 4 Oct 2026
Privacy and cookies: The site says it uses cookies and similar technologies, offers consent controls, and says IP addresses are needed for main features and stored for legal claims. · issemantic.net, 8 Oct 2026
Purpose: isSemantic.net validates, visualizes, generates and converts structured data on websites. · issemantic.net, 8 Oct 2026
RDF conversion: The converter can take data from a web address or pasted markup and can auto-detect the input format. · issemantic.net, 8 Oct 2026
RDF converter: The converter accepts a web address or code snippet, can auto-detect input format and converts between RDF serialization formats including RDF-star formats. · issemantic.net, 4 Oct 2026
RDF formats: The visualizer supports formats including JSON-LD, Microdata, N-Quads, N-Triples, N3, RDFa, RDF/XML, TriG and Turtle. · issemantic.net, 8 Oct 2026
RDF-star support: RDF-star conversion and validation are supported, but the site describes this support as provisional because RDF-star is an unofficial draft. · issemantic.net, 8 Oct 2026
RDF visualization: The visualizer displays RDF triples as a graph and lists their relations in a table, in the browser without software installation. · issemantic.net, 8 Oct 2026
RDF visualizer: The visualizer displays RDF data as a graph and also lists triples in a table and hierarchical view. · issemantic.net, 4 Oct 2026
Result disclaimer: The validator says it does not guarantee that correctly marked-up data will appear in search results. · issemantic.net, 8 Oct 2026
Service limitation: The site does not guarantee that correctly validated structured data will appear in search results. · issemantic.net, 4 Oct 2026
Support: The maker provides a Contact us link and says users with queries about the terms can contact them, but the opened pages do not state a support response commitment. · issemantic.net, 4 Oct 2026
Usage terms: The terms restrict use to private, non-commercial purposes and say access may be suspended, restricted or terminated at any time without notice. · issemantic.net, 4 Oct 2026
Use restriction: The terms state that use is for private, non-commercial purposes and that accessed third-party structured data is not stored or redistributed. · issemantic.net, 8 Oct 2026
Validation formats: The validator accepts JSON-LD, RDFa and Microdata. · issemantic.net, 8 Oct 2026
Validation limitation: Markup using vocabularies beyond Schema.org is shown in an Other vocabulary markup section and is not validated by the tool. · issemantic.net, 8 Oct 2026
Validator: The validator checks Schema.org, Google Search, Facebook Open Graph, Twitter Cards, Facebook App Links and HTML heading semantics. · issemantic.net, 8 Oct 2026
Validator limitation: Markup using vocabularies other than Schema.org is shown in an “Other vocabulary markup” section rather than validated. · issemantic.net, 4 Oct 2026

Where isSemantic.net stands on Freedom251

Schema Markup Tools#11 of 24