JSON Schema Validator — Draft-07 Data Contract & Syntax Testing Studio

The validator is specifically built to support JSON Schema Draft-07, which is the most widely adopted and stable schema standard across enterprise software frameworks, OpenAPI 3.0 tooling, and backend libraries (including Python Pydantic, Java Jackson, Go jsonschema, and Node.js environments). It supports core Draft-07 keywords including type assertions, required arrays, properties, additionalProperties, minLength/maxLength, minimum/maximum, exclusiveMinimum/exclusiveMaximum, multipleOf, pattern, format (email, uri), enum, const, and array assertions (items, minItems, maxItems, uniqueItems).

The engine traverses nested hierarchies recursively and generates unambiguous dot-notation and bracket-notation property paths for every violation. For example, if an error occurs within an object located inside an array, the path is explicitly rendered as 'company.employees[3].contact.email'. Top-level schema failures are pinpointed with '(root)', allowing developers to instantly locate and fix defective values in multi-megabyte payloads.

JSON syntax validation solely checks whether a string conforms to basic JSON grammar (IETF RFC 8259)—verifying that braces match, strings are enclosed in double quotes, and numbers are correctly formed. JSON Schema validation occurs after syntax validation and checks structural business rules—enforcing that specific properties exist, data types match contract declarations, numeric values fall within legal thresholds, and strings conform to specific formats or regular expressions.

In Draft-07, 'additionalProperties: false' strictly inspects properties defined directly under the immediate 'properties' keyword at that exact hierarchy level. If properties are declared inside separate sub-schemas or if there is a typographical mismatch in the property key name, the validator will flag them as illegal additional properties. Ensure that every permissible key for that level is explicitly enumerated under the 'properties' dictionary.

No. The validator operates on a 100% client-side serverless architecture. All parsing, regular expression matching, and schema traversal logic execute purely within your browser's local JavaScript memory thread. Not a single byte of your payload or schema is transmitted over the network, making it completely safe for confidential production data, API secrets, customer records, and HIPAA/GDPR-regulated datasets.

Yes. The validator fully supports array-based union types in accordance with Draft-07. For example, defining '"type": ["string", "null"]' allows a property to accept either a valid string or an explicit null literal. Similarly, '"type": ["number", "integer"]' or polymorphic unions across primitive types are validated with complete type safety.

The engine compiles the value specified under the 'pattern' keyword into a native JavaScript RegExp object and tests the target string using RegExp.test(). If your regex contains special escape sequences (such as '\\\d' or '\\\w'), ensure they are double-escaped in raw JSON text so that JSON.parse does not strip the backslash prior to compilation. Malformed regex patterns are safely handled without halting the validator.

The studio features defensive syntax guardrails. Before initiating schema evaluation, it parses both input panels using safe string parsing. If either panel contains malformed syntax—such as unquoted keys, trailing commas, or unclosed brackets—the engine intercepts the error and displays a clear diagnostic badge highlighting the exact syntax error message, preventing application crashes.