JSON Schema starter
Infer a starter JSON Schema from sample JSON.
Inputs stay in your browser. Builds a draft from primitives, arrays, objects, and required keys.
This is a starter schema only; it does not infer formats, constraints, optionality, or business rules.
How to use this tool
Infer a starter JSON Schema from sample JSON.
Infer a starter schema from a sample JSON object, then manually refine the data contract.
💡 3 Quick Steps to Get Started
Paste a test object such as {"id":1,"tags":["admin"]}.
Generate type, properties and required. Observed object properties are fixed as required; there is no toggle.
Download json-schema.json and test it with your chosen validator and dialect.
When it helps
Useful for API docs, form validation, and data contract drafts.
How it works
Builds a draft from primitives, arrays, objects, and required keys.
Worked example
Example: paste a user JSON object to generate schema.
Limits and data handling
One sample cannot express every valid variation; add optional fields, formats, and constraints before publishing.
No. The JSON Schema starter runs in the browser. Do not paste production secrets or unredacted personal data.
JSON Schema starter guide
Workflow and limits
Paste a test object such as {"id":1,"tags":["admin"]}.
Generate type, properties and required. Observed object properties are fixed as required; there is no toggle.
Download json-schema.json and test it with your chosen validator and dialect.
Arrays sample only the first 50 elements when merging inferred types. Nesting is limited to 100 and input to 100000 characters.
No $schema dialect declaration, format, numeric constraints, business rules or complete optionality inference is generated. Validator compatibility requires separate testing.
Feedback
How can we improve this tool?
Send a suggestion or bug report for this tool.
FAQ
What input does the JSON Schema starter accept?
Paste one valid sample JSON object; root arrays and primitives are not accepted.
How does the JSON Schema starter produce its result?
It infers primitive, object, array, and required-key structure from that sample.
What are the JSON Schema starter limitations?
One sample cannot express every valid variation; add optional fields, formats, and constraints before publishing.
Does the JSON Schema starter upload data?
No. The JSON Schema starter runs in the browser. Do not paste production secrets or unredacted personal data.
