JSON Schema Validator
Validate JSON against a draft-07 or 2020-12 schema. Review error paths without sending the documents to a server.
Open toolJSON Schema Generator from JSON
Infer a draft-07 JSON Schema from a JSON object or nonempty array of objects. Review field types and required entries before using the schema as a data contract.
Free to useNo sign-upRuns in your browser
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Enter the inputs, then select Generate schema.
Your result
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Result will appear here
How JSON Schema Generator from JSON works
Use quicktype to infer field types and nested object shapes and emit JSON Schema draft-07.
Sample inference does not establish all allowed values, optional fields or business rules. The generated schema may need edits for additional examples and desired constraints. No remote schema or sample is fetched.
How to use JSON Schema Generator from JSON
Use a representative JSON object or object array, choose the root type name, and review the inferred draft-07 schema.
Paste a representative JSON sample
Use an object or a nonempty array of objects and choose a root type name. Include examples of optional and nullable fields where possible.
Input and settings
Generate schema
Select Generate schema to infer a draft-07 schema from the supplied object shapes and values. The generator uses only your pasted sample; it does not retrieve your API or a remote schema.
Tool result
Review and download the generated JSON Schema
Generate the schema, then review definitions, field types and required entries. Download schema.json and validate representative data separately.
Review the details
Generate JSON Schema for nested API payload samples
Start a schema from an example and refine it against your complete data contract.
Start a draft-07 schema
Use a sample to create an initial schema structure. Add ranges, patterns and rules from your actual data contract after generation.
Describe nested payload shapes
Generate definitions for objects and arrays in an API example. Check that additional real responses fit the inferred structure.
Pair generation with validation
Open JSON Schema Validator to test the edited schema against valid and invalid documents. A successful sample does not prove that every allowed case is covered.
Draft-07 schema types and required fields
Read inferred types and required entries as a starting point for the contract your application actually needs.
The schema is draft-07. It describes shapes inferred from supplied examples; it does not know which missing values your application should allow.
Review optional fields, numeric ranges, and sample coverage
An observed JSON sample does not establish all valid values, optional fields or business rules.
Review required fields, empty arrays and numeric ranges. Add business rules yourself instead of treating one observed sample as the complete contract.
The JSON input is limited to 100,000 characters and must be an object or a nonempty array of objects. Use a root type name beginning with a letter and containing at most 40 letters, digits or underscores; reserved names are rejected. After editing the schema, validate additional representative documents separately.
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Open toolJSON Schema Generator from JSON: common questions
Answers about using JSON Schema Generator from JSON and understanding its results.
What schema draft is generated?
The output uses JSON Schema draft-07.
Does one sample prove a field is always required?
No. Review required fields and inferred types with your complete data contract.
Generate schema with your own input
Infer a draft-07 JSON Schema from a sample object or object array, then review it before using it as a contract.