JSON Schema Generator: Draft 2020-12 from Samples
Infer a local JSON Schema from all sample values, review nested types and required fields, and export Draft 2020-12 without pretending to validate a contract.
Enabling local controls…
1. Enter a JSON sample
Processed only in this browser: no upload, storage or URL state. Input: 1 MiB, 100 levels, 50,000 nodes; schema: 10,000 nodes, 2 MiB; 5-second timeout.
This is a starting point inferred from one sample, not a complete contract or schema validator. Observed keys default to required; review against the real contract. A sample cannot establish format, regex, enum, examples or safety guarantees.
2. Review and adjust schema
Enter or load a sample, then generate a schema.
How to use this tool
Infer from a JSON sample, select a schema path and adjust its type or required status. Empty arrays keep unknown items; array object samples merge observed properties and intersect required keys. Export the complete schema after review.
When not to use it
Sample inference is not a complete API contract or schema validation. No guessed formats, patterns, enums or automatic additionalProperties:false. Required defaults describe observed samples, not future responses.
Read the guide →