Supports type validation, required properties, string formats (email, uri, uuid), min/max constraints, patterns, and enum values.
How to Validate JSON Against a Schema
- 1
Paste Your JSON Schema
Enter or paste your JSON Schema definition into the left panel. The schema describes the expected structure including property types, required fields, constraints, and formats. You can also click Load Sample to start with a working example. - 2
Enter the JSON Data
Paste the JSON data you want to validate into the right panel. This is the actual payload, API response, or configuration file you want to check against your schema definition. - 3
Click Validate
Hit the Validate button to run the validation. The tool checks every constraint in your schema against the data, including type mismatches, missing required properties, format violations, and value range errors. - 4
Review Validation Results
If the data passes, you see a success message. If it fails, each error is listed with a clear description and the path to the offending property, so you can fix issues quickly without guessing which field is wrong.
Common Use Cases
API Request and Response Validation
Configuration File Validation
Data Pipeline Quality Checks
Schema Development and Testing
Why Use JSON Schema Validator?
JSON Schema is the industry standard for describing the structure and constraints of JSON data. It defines which properties are required, what types they must be, acceptable value ranges, string formats, and nesting rules. Using a JSON Schema validator lets you catch structural errors, type mismatches, and missing fields before they cause runtime failures in your application.
This free online JSON Schema validator supports Draft-07 and checks your data against every constraint in your schema, including type validation, required properties, string formats like email and URI, numeric minimum and maximum bounds, array length constraints, pattern matching, and enum restrictions. All validation runs entirely in your browser, so your data never leaves your machine. There are no file size limits, no signup, and no usage caps.
For related workflows, use the JSON Schema Generator to automatically create a schema from existing JSON data, or the JSON Formatter to clean up and validate JSON syntax before running schema validation. If you need to convert your validated JSON into typed code, try the JSON to TypeScript Converter or the JSON to Zod Schema tool for runtime-safe type validation in JavaScript and TypeScript projects.
How It Compares
Most online JSON Schema validators send your data to a remote server for processing, which creates privacy risks when validating API keys, tokens, user data, or internal configuration files. This tool runs entirely client-side in your browser. Your JSON data and schema never leave your machine, making it safe for validating sensitive payloads.
Unlike command-line validators like ajv-cli or jsonschema, this tool requires no installation, no package manager setup, and no terminal commands. Paste your schema and data, click Validate, and get instant results with clear error messages pointing to the exact property path. It is free to use with no account required, no rate limits, and no ads.