JSON Validator & Schema Checker
Strictly validate JSON with precise line and column error messages. Optionally validate data against a JSON Schema. Free online JSON validator.
Validate JSON and JSON Schema
Use the JSON validator to catch syntax errors with precise, line-and-column messages, then optionally validate your data against a JSON Schema to enforce structure, types and constraints.
JSON Schema validation is especially useful when building APIs, processing third-party data or writing integration tests. The validator supports JSON Schema draft-07 keywords including type, required, properties, enum, minimum/maximum, pattern, format and all four logical combinators. Errors are reported with the JSON path to the failing field so you can jump straight to the problem.
Frequently asked questions
What does the validator check?+
It strictly validates JSON syntax and reports precise line and column error messages. You can also validate your data against a JSON Schema.
Which JSON Schema features are supported?+
Common draft-07 keywords including type, required, properties, enum, const, minimum/maximum, string length, pattern, format and the anyOf/allOf/oneOf/not combinators.
What is JSON Schema?+
JSON Schema is a vocabulary for describing the structure, types and constraints of JSON documents. It lets you define what keys are required, what types values must be, what ranges numbers must fall in, and more — then automatically validate data against those rules.
Which JSON Schema draft is supported?+
The validator supports JSON Schema draft-07, which is the most widely used version and covers the vast majority of real-world schemas including type, required, properties, additionalProperties, enum, const, minimum, maximum, pattern, format, and the anyOf/allOf/oneOf/not combinators.
What do the error messages show?+
Each error shows the JSON path to the failing value (e.g. /users/0/email), the schema keyword that was violated, and a human-readable explanation. For syntax errors the line and column number are also shown.