BYTETOOLS

JSON Schema Validator

Validate JSON against a JSON Schema online. Checks type, required, properties, enum, pattern and more, listing every failure with its JSON Pointer.

What is the JSON Schema Validator?

The ByteTools JSON Schema Validator checks a JSON document against a JSON Schema and lists every failure with its exact JSON Pointer path, the keyword that failed and a plain-English message.

  • Core draft keywords: type, required, properties, items, enum, const
  • Numeric, string, array and object constraints (pattern, bounds, uniqueItems)
  • Every failure reported with its JSON Pointer path
  • additionalProperties enforcement, boolean or schema form
  • Unsupported keywords listed openly instead of silently ignored
  • 100% private — schema and data never leave your browser

How to use the JSON Schema Validator

  1. 1

    Paste your JSON Schema into the left box.

  2. 2

    Paste the JSON document to check into the right box.

  3. 3

    Click Validate.

  4. 4

    Review each failure's JSON Pointer path and message, and note any ignored keywords.

About the JSON Schema Validator

The ByteTools JSON Schema Validator checks a JSON document against a JSON Schema and lists every failure with its exact JSON Pointer path, the keyword that failed and a plain-English message. It covers the core keywords: type (including integer), required, properties, items (single and tuple form), enum, const, minimum/maximum with exclusive variants, multipleOf, minLength/maxLength, pattern, additionalProperties, min/maxItems, uniqueItems and min/maxProperties.

It is the consumer-side companion to our JSON Schema Generator: paste a schema and a candidate document side by side, hit Validate and immediately see which fields break the contract — ideal for debugging API payloads, config files and webhook bodies.

The validator is transparent about scope: keywords it does not evaluate (like $ref, allOf or format) are reported as ignored rather than silently skipped. Validation runs 100% locally in your browser — neither the schema nor the document is ever uploaded or stored.

Frequently asked questions

How do I validate JSON against a schema?

Paste the schema in one box and the document in the other, then click Validate. The tool walks both together and lists every violation with a JSON Pointer such as /items/2/price, the failing keyword and what was expected.

What is a JSON Pointer path?

It is the standard way (RFC 6901) to address a location inside a JSON document — /users/0/email means the email key of the first element of users. Each reported failure uses one so you can jump straight to the broken field.

Which schema keywords are supported?

type, required, properties, items, enum, const, minimum/maximum and their exclusive forms, multipleOf, minLength/maxLength, pattern, additionalProperties, minItems/maxItems, uniqueItems and minProperties/maxProperties. That covers the great majority of real-world schemas.

Does it resolve $ref or combine allOf/anyOf/oneOf?

No — composition and reference keywords are not evaluated. When a schema contains them the tool says so explicitly in the results, so a 'valid' verdict is never based on rules it quietly skipped.

What does 'integer' mean versus 'number'?

number accepts any JSON numeric value, while integer requires a whole number: 5 passes but 5.5 fails. The validator implements exactly this distinction.

Is my data uploaded for validation?

No. Both schema and document are processed with JavaScript in your browser tab and never transmitted or stored anywhere.

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