What JSON Schema does
Syntactically valid JSON can still violate an API contract. This tool compares instance data with a schema and reports type, required, properties, items, and composition failures at their JSON paths.
Common uses
- Check API request and response shapes
- Validate required configuration fields and types
- Preflight common rules before publishing a schema
Privacy and limitations
Both the data and schema are validated locally. Confirm complex and remote-reference behavior with the authoritative validator used by your target platform.
Always validate security-sensitive output in the authoritative application or platform.
Frequently asked questions
Which JSON Schema version is supported?
The validator targets commonly used Draft 2020-12 keywords, including type, required, properties, items, enum, numeric and string constraints, composition rules, and local references.
Does it fetch remote $ref URLs?
No. It only resolves local references beginning with #/ inside the current schema, so the tool never contacts a referenced host.
Should a server validate the same input again?
Yes. Client validation improves feedback but is not a security boundary. The server must validate untrusted input against its own trusted schema.