Free Tools/JSON Schema Validator
1Validate schema
2Auto-validate in production

JSON Schema Validator

Validate any JSON against a JSON Schema (draft-07). Powered by Ajv — the fastest JavaScript validator. Free, no signup.

JSON Schema draft-07Ajv poweredAll formatsDeep errors

Stop validating manually. Svivva does this on every API call.

Svivva wraps your AI endpoint with your JSON Schema — every response is validated automatically, and if it fails, the AI self-repairs before your users ever see it. Zero validation failures, no extra code.

Auto-validate in production — free

About JSON Schema Validation

What is JSON Schema?

JSON Schema is a vocabulary for annotating and validating JSON documents. It lets you define the expected structure, types, required fields, and constraints for any JSON data.

Which JSON Schema drafts are supported?

This validator uses Ajv which fully supports JSON Schema Draft-07 (the most widely used draft), with partial support for Draft-2019-09 and Draft-2020-12.

What formats are supported?

All standard formats from ajv-formats: email, date, date-time, uri, ipv4, ipv6, uuid, hostname, byte, binary, password, regex, and more.

How do I validate model responses automatically?

Svivva lets you define a JSON Schema for your AI endpoint — every response is automatically validated, and if it fails, the AI auto-repairs the output before returning it to your users.

Can I use additionalProperties: false?

Yes — this is fully supported and is one of the most useful constraints: it rejects any JSON that contains keys not defined in your schema's 'properties'.