Invalid Example: Field Has the Wrong Type
Check one JSON value against a small subset of JSON Schema: types, ranges, required keys, properties, items, pattern, and enum.
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Result
About this tool
This page opens the JSON Schema validator preloaded with the same user-profile schema as the valid preset — requiring id, email and age, with age typed as an integer — but with a JSON payload where age is written as the string "thirty-four" instead of a number. Validation runs on load, so the failure shown below is a real, live check of this exact pair.
A field that's present but has the wrong type is a different failure mode from a missing field, and it's just as common in practice: form data submitted as strings without being converted to numbers, a CSV import that never parses numeric columns, or an API client that serializes everything as text. The schema's type: "integer" rule on age requires a JavaScript number that is also a whole number, and a quoted string never satisfies that, no matter what it contains.
The error message below identifies exactly which field failed and why, including its path inside the object. Compare this preset against valid-user-profile-schema, where age is a genuine integer, and against missing-required-field-schema for the other common validation failure — a required key that's absent altogether rather than present with the wrong type.
Example. The value {"age": 15} against a schema that requires name and an integer age of at least 0 fails with Required property "name" is missing. {"name": "Ada", "age": 15} against that schema passes.
Limit. Only type, minimum, maximum, minLength, maxLength, pattern, enum, required, properties, and items are applied. $ref, combinators, format, and additionalProperties are ignored, and a bad pattern is skipped.