JSON Schema validator
Validate a JSON against a JSON Schema and see each error with its exact path, or generate a schema from a sample JSON.
How to useValidate JSON against a schema.
Available in: 
JSON Schema validator: what it is for
Paste the JSON Schema and the JSON and instantly see whether it is valid. Each error shows the exact field path (such as /items/2/price) and the rule that failed: missing required field, wrong type, minimum value, text pattern and more. The Generate schema button creates a starting schema from a sample JSON, with types and required fields.
Everything runs in your browser: nothing you paste or open is sent to a server.
How to use
- Paste the JSON Schema on the left.
- Paste the JSON on the right.
- Fix the errors shown by path.
When to use it
- Test API contracts.
- Validate configuration files.
- Create a schema from an example.
Frequently asked questions
Which JSON Schema versions work?
Validation uses Ajv with draft 2020-12, which also accepts the vast majority of schemas written for draft-07 and 2019-09. The $schema field is ignored so it does not block validation.
What does Generate schema do?
It reads the JSON on the right and builds a basic schema with the type of each field and the list of required fields. It is a starting point for you to add formats, limits and enums.
Does my data leave the browser?
No. Validation runs entirely in your browser.
Is it really free?
Yes, 100% free. No sign-up, no subscription and no usage limits. All Tools123 are free.