JSON Schema Infer
Walk a JSON document and emit a draft schema that describes it. Round-trips with json-schema-validate — infer a schema, then validate the same document and the result is `valid: true`.
About JSON Schema Infer
JSON Schema Infer walks any JSON document and produces a draft schema that describes its shape, types, and structure. It's the fastest way to bootstrap a schema from real data instead of writing one by hand, and it round-trips cleanly: infer a schema here, validate the same document against it, and you'll get valid: true. It runs entirely in your browser, so your data stays private while you scaffold the schema.
- Category
- inspect
- Input
- Accepts: application/json or text/plain.
- Output
- Outputs: application/json.
- Cost
- Free, runs in your browser
- Memory
- low
Common uses
- Bootstrap a JSON Schema from a sample API response instead of authoring it from scratch
- Generate a starting schema for a config file, then tighten the constraints by hand
- Document the implied structure of an undocumented JSON feed for your team
- Produce a draft contract for a webhook payload you just started receiving
- Create a baseline schema for test fixtures so future changes get caught
- Reverse-engineer the shape of a large JSON blob you didn't design
Frequently asked questions
How does this relate to JSON Schema Validate?
They're designed to pair: a schema inferred here will validate the same document as valid in JSON Schema Validate, so you can round-trip between the two.
Is the inferred schema final?
It's a draft that describes the sample you provided. You'll usually want to refine it, for example tightening required fields or adding value constraints, before treating it as your contract.
Does my JSON leave my device?
No. The document is walked and the schema is generated locally in your browser; nothing is uploaded.
What input does it accept?
It takes application/json or plain text, so you can paste JSON directly or drop a file.
What if my JSON has arrays of mixed shapes?
The inferred schema reflects the structure it observes in your sample; arrays with varied shapes produce a broader schema that you may want to narrow manually.
Keywords
- json
- schema
- infer
- generate
- jsonschema
- derive