JSON Schema Validator
Paste JSON data and a JSON Schema to validate it locally. Errors include the path and the rule that failed.
About JSON Schema Validator
Validate JSON against a JSON Schema online and get precise error paths and messages for every failing rule. This free JSON Schema validator helps you test required properties, data types, enums, formats, nested object constraints, and array item rules before your data reaches an API or database. It is useful for debugging request payloads, OpenAPI models, and configuration contracts.
API designers paste a schema and a sample body to see why a gateway rejected a request. Frontend developers check form output against the contract. QA builds fixtures that should fail on purpose and confirms the right path is reported. Backend teams reproduce a production validation error without standing up the service. Error paths make nested failures obvious, such as items[2].email rather than a generic invalid payload.
Provide both the schema and the instance JSON. When they are valid together, you get a clear pass. When they are not, you get rule-level messages you can fix in either the data or the schema. This is more precise than only checking that JSON parses. Pair it with the JSON viewer or JSON beautifier to inspect the instance while you work.
Your schema and data are validated in your browser and never uploaded. Internal API contracts stay on your device. Use this free online JSON Schema validator whenever you need path-accurate, private schema checks.
Features
- Validate JSON data against a JSON Schema
- Paste text or load a file and get a result in one click
- Copy or download the output for your project
- Input for JSON Schema Validator is processed in your browser
- No signup and no intentional server-side storage of tool input
How to use JSON Schema Validator
- Paste text or load a file into JSON Schema Validator.
- Choose the format, compare, validate, or convert action you need.
- Copy the result or download it for your project.
- Input is processed in your browser and is not uploaded for this tool.
Suggested next steps
- JSON Beautify — Pretty-print JSON with 2, 3, or 4 space indent
- JSON Viewer — Inspect, format, and browse JSON
- JSON Path Tester — Query JSON with JSONPath expressions
Frequently asked questions
Is JSON Schema Validator free?
Yes. JSON Schema Validator on Free Tool Mate is free to use in your browser. There is no paid unlock for the core tool features described on this page.
Does JSON Schema Validator upload my data?
No. JSON Schema Validator is designed to process your input locally in the browser. Free Tool Mate does not intentionally store tool input or uploaded files on the server.
Do I need an account to use JSON Schema Validator?
No account is required. Open the page, use JSON Schema Validator, and leave when you are done.
What can I use JSON Schema Validator for?
JSON Schema Validator covers Validate JSON data against a JSON Schema. It is built for quick, private work in the browser without installing desktop software.