AscendLab

Developer tools

JSON Schema 生成器

Free browser tool

JSON Schema Generator from JSON Sample

Infer a starter JSON Schema from pasted JSON without sending data to a server. Use it for API docs, config validation drafts, typed payload reviews, and handoff notes.

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Quick answer
A JSON Schema generator turns a sample payload into a copy-ready schema draft.
Best inputs

Representative payloads

Use a real object that includes fields your schema should describe.

API examples

Start from response samples, config files, webhook events, or test fixtures.

Example, assumptions, and limitations
Generated schemas are useful drafts, not complete production validators.

Example

A JSON object with id, name, tags, and owner fields becomes an object schema with nested properties.

Assumption

The sample represents the shape you expect future payloads to follow.

Limitation

The tool cannot infer business rules, optional variants, enums, formats, or all array item possibilities.

Frequently asked questions

Which draft is used?

The generated schema uses the JSON Schema draft 2020-12 $schema URL.

Can it infer optional fields?

It can omit required arrays when that option is off, but it cannot know optional production fields that are missing from the sample.

Can I include examples?

Yes. Turn on examples to include the pasted JSON as a schema example.

Does it need a backend?

No. JSON parsing and schema generation happen locally.

Suggested workflow

JSON schema path

Clean the payload, generate a schema draft, then inspect paths or format the result.

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