Schema.biz vs VitalSentinel Schema Validator

Schema.biz is a free browser toolkit for structured data markup, database schemas, and API specifications. Its markup tools generate, validate, and optimize JSON-LD, Microdata, and RDFa. A visual schema designer exports SQL for PostgreSQL, MySQL, SQLite, and SQL Server; database tools also diagram CREATE TABLE statements, compare schema versions, visualize queries, and offer templates. API tools validate JSON Schema, edit OpenAPI specifications, generate schemas and mock data, convert formats, and detect breaking changes. An AI Search Optimizer checks structured data readiness for ChatGPT Search, Perplexity, and Google AI Overviews. Pasted data is processed in browser JavaScript, and the maker says it is not sent to its servers. For URL-based markup checks, however, the server fetches the requested page for the browser to inspect. The free plan includes all tools without feature gates, limits, or signup. Persistent cross-device work and third-party URL crawling are not offered; an API Validator and Mock Server are marked as coming soon.

VitalSentinel Schema Validator checks structured data on a page URL and separates missing, recommended and broken information. It examines JSON-LD blocks individually, including nested entities and entities within an @graph. For broken blocks, it identifies line and column and names common causes such as trailing commas, curly quotes and HTML entities. Its property checks distinguish Google-required from recommended fields for Article, Product, FAQPage, Recipe, Event, BreadcrumbList, LocalBusiness and Organization; other listed types are not graded. It also flags non-absolute image URLs, dates outside ISO format and prices containing a currency symbol. The free checker reads server-sent HTML, so it cannot see JSON-LD inserted by JavaScript. It reports microdata and RDFa when present but does not grade them. A valid result does not guarantee a Google rich result, and the tool recommends Google's Rich Results Test for rendered pages and eligibility checks. It is available on web and via API. The plan list includes a free plan and Starter at $39 a month.