JSON to JSON Schema
The JSON to JSON Schema generator infers a schema from a sample document. Fields that appear in several places are merged, and required properties are marked, so you get a usable draft-07 schema without writing it by hand. Paste your JSON and the schema is generated locally in your browser — nothing is uploaded.
How to use it
- 1
Paste sample JSON
Provide a representative document. More samples give a more accurate schema.
- 2
Generate the schema
The generator infers types and structure and merges similar fields across the sample.
- 3
Review required properties
Properties present in the sample are marked as required; adjust by hand where your data allows them to be missing.
- 4
Copy the schema
Use the draft-07 schema for validation, documentation or code generation.
Key features
Automatic inference
Types, nesting and arrays are inferred from your sample in one step.
Field merging
Common fields are merged so array items share a single, coherent definition.
Required detection
Properties found in the sample are marked required, so you start from a runnable schema.
Standard draft-07
Output follows the widely supported draft-07 specification.
Local and private
Generation runs in your browser; your data is never uploaded.
Feeds validation
Use the resulting schema with the JSON Schema validator or your own tooling.
Common errors & troubleshooting
- ! Include every field you expect in the sample, or they will be missing from the inferred schema.
- ! Fields that appear in some array items but not others are inferred as optional; representative samples reduce noise.
- ! Inferred schemas are a starting point — tighten them with enums, formats and constraints by hand.
- ! Very large integers can lose precision in JavaScript, which may affect the inferred type.
Frequently asked questions
Which JSON Schema draft is produced?
The generator emits draft-07, which is widely supported by validators and tooling.
Is my JSON uploaded to infer the schema?
No. Inference runs locally in your browser; your document never leaves your device.
Why are some fields marked required?
Properties present in the sample are treated as required by default. Edit them if your data allows them to be absent.
Can the schema be used to validate data?
Yes. The generated draft-07 schema can be used directly with the JSON Schema validator on this site or any compliant validator.
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