JSON Schema Validator

A JSON Schema describes the shape your data is supposed to have — which fields are required, what types they hold, what ranges and patterns are allowed — and validating against it catches malformed payloads before they break an API or a config loader.

This validator lets you paste a schema and a JSON document side by side and instantly see whether the data conforms, with a precise list of every problem found.

It supports the keywords you reach for most often in draft-07-style schemas: type (including unions and the integer/number distinction), required, properties, enum and const, the numeric bounds minimum, maximum, exclusiveMinimum, exclusiveMaximum and multipleOf, the string checks minLength, maxLength and pattern, and the array checks items, minItems, maxItems and uniqueItems.

It also understands additionalProperties:false and min/maxProperties on objects.

Each failure is reported with a JSON-Pointer-style path such as /users/0/email so you can jump straight to the offending value.

This is a deliberately lightweight, client-side checker rather than a fully spec-compliant engine — there are no $ref resolutions or remote schema fetches — which keeps it fast, fully offline and completely private.

Nothing you paste is uploaded, logged or stored; the validation happens entirely in your browser, so it is safe for sensitive configuration and production payloads.