JSON Schema Validator

When an API rejects your payload with a bare "invalid request", a JSON Schema validator is how you find out *which* field broke the contract. Paste your JSON document on the left, the schema it should satisfy on the right, and every violation comes back as a list: the exact JSON Pointer to the offending value, the keyword that failed (type, required, enum, pattern, ...), and a plain-English explanation.

Two things make this validator nicer to debug with than most. First, it does not stop at the first failure — you get the full error list (up to 100 entries) in one pass. Second, a broken schema is reported separately from a failing document: if your schema itself can't compile (invalid JSON, a bad regex pattern, an unresolved remote $ref), you see that as a distinct schema error instead of a confusing pile of validation failures.

Validation follows the JSON Schema 2020-12 draft and resolves local $refs only — pointers like #/$defs/address work, remote URLs are never fetched. Format keywords (email, date-time, uuid, ...) are treated as annotations: mismatches show up as warnings, not hard errors, matching the behavior of most production validators.

FAQ

Which JSON Schema draft is supported?

Draft 2020-12. That includes prefixItems, $defs, unevaluatedProperties and the other modern keywords. Older drafts mostly validate as expected since their common keywords are unchanged.

Are remote $refs fetched?

No. Only local references (#/... pointers into the same schema document) are resolved. A schema that depends on a remote reference fails with a clear compile error — inline the referenced schema under $defs to validate locally.

Is my data uploaded?

No. Validation runs entirely in your browser. You can load the page, disconnect, and keep validating.