About JSON Schema validation
This tool checks whether a JSON document is valid against a JSON Schema. Paste your schema and data and it tells you instantly if the data conforms, listing any errors with the path that failed. It uses the Ajv validator (JSON Schema draft-07) and runs entirely in your browser.
How JSON Schema Validator works
How to use it
- Paste your JSON Schema on the left.
- Paste the JSON data to check on the right.
- See the valid/invalid result and any errors update as you type.
How it works
JSON Schema is a standard way to describe the shape of JSON — required fields, types, formats and constraints. The validator compiles your schema and checks the data against every rule, reporting each failure with the location in the document.
Good for
Testing API request and response payloads, validating configuration files, and confirming a schema behaves as you expect before using it in code.
Common uses
- Validate JSON against a schema
- Test API payloads
- Check configuration files
- Debug a JSON Schema
- Confirm required fields
- Verify data types
- Catch malformed data
- Learn JSON Schema
Frequently asked questions
How do I validate JSON?
Paste a schema and a JSON document; the result shows instantly.
Which schema version is supported?
JSON Schema draft-07 via the Ajv validator.
Is my data uploaded?
No — validation runs entirely in your browser.
What do the errors mean?
Each error shows the path in the data and why it failed the schema.
Can it validate nested objects?
Yes — it validates the full structure, including nested data.
Does it check formats like email?
Common constraints are checked; some formats need extra options.
Why is it invalid when it looks right?
Check required fields, types and the exact paths in the errors.
Is it free?
Yes — completely free with no sign-up.