How to use the JSON Schema Validator
1. Paste your JSON Schema on the left (draft-07 format).
2. Paste the JSON data to validate on the right.
3. Click Validate — all errors are listed with the exact path where each violation occurred.
What is it?
This validator checks JSON against a schema definition. Supported keywords: type, required, properties, items, additionalProperties, enum, minLength, maxLength, pattern, minimum, maximum, multipleOf, minItems, maxItems. It covers the most common validation scenarios for REST API development and form validation.
Benefits
Catch structural errors before they reach production
Validate JSON, XML, and YAML syntax and schema compliance interactively — find missing required fields, wrong types, and broken structure before deploying config or API changes.
Test patterns against real input, not assumptions
Write a regex, a schema constraint, or an IP validation rule and test it against actual edge cases — empty strings, Unicode, long inputs — before a single line of code is written.
Pinpoint exactly what changed between two versions
Line-by-line diff highlights additions, deletions, and modifications between config file versions, API response snapshots, or document drafts — faster than reading both manually.
Validate interactively instead of adding debug logs
Confirm that a regex, schema, or config file is correct in the browser — not by deploying, adding print statements, and waiting for a runtime error.
Frequently asked questions
What keywords are supported?
type, required, properties, additionalProperties, items, enum, minLength, maxLength, pattern, minimum, maximum, multipleOf, minItems, maxItems — covering the most used draft-07 keywords.
What about $ref and allOf/anyOf/oneOf?
These advanced composition keywords are not yet supported in this client-side implementation. For complex schemas, use ajv in your codebase.