JSON Schema Validator

Paste a JSON Schema on the left and the JSON data to check on the right.

JSON Schema Open file

JSON data Open file

Validation result

Supported keywords

type, enum, const, required, properties, patternProperties, additionalProperties, items/prefixItems, minItems/maxItems, uniqueItems, contains, minLength/maxLength, pattern, format (email, uri, date, date-time, time, ipv4, uuid), minimum/maximum, exclusiveMinimum/exclusiveMaximum, multipleOf, minProperties/maxProperties, allOf, anyOf, oneOf, not, if/then/else, and local $ref (#/definitions/… or #/$defs/…).

Reading the errors

Each problem shows where it is, written like $.address.city or $.items[2] ($ is the top of the document), and what is wrong. For example: "Missing required property \"email\"" or "Should be ≥ 18". Fix the data (or the schema) and the result updates as you type.

Limits

Remote $ref URLs are not fetched, and vocabulary-specific keywords such as unevaluatedProperties and dependentSchemas are not checked. For production code use a full validator library such as AJV (JavaScript) or opis/json-schema (PHP). This tool is for quick checks while you write a schema or debug an API payload. Your data stays in your browser.

Free to useNo software to install — works in any modern browser.

No signup neededOpen the tool and start straight away.

Your file stays on your deviceEverything happens in your browser — nothing is uploaded.

Works on mobileSame tool on your phone, tablet or desktop.

How it works

Open — choose your file; it stays on your device.
Work — make your changes right in the browser.
Save — download the result straight to your device.

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