JSON type inference tree

Client

Paste sample JSON and read an inferred type tree—nested objects, array element shapes, and primitive fields—before you open a codegen or schema tool.

Nearby workflows on Toolcore

  • JSON Schema validateValidate JSON against a schema, infer draft-07 schema from data—Ajv in browser. once JSON text parses on this page.
  • Compare JSON shapesCompare inferred shapes of two JSON samples—added paths, missing fields, type changes—local. once JSON text parses on this page.
  • JSON formatterJSON format online: pretty-print, minify, validate, escape, download . once JSON text parses on this page.

Common use cases

  • Skim API response shapes during integration without writing TypeScript yet.
  • Compare two fixture files with the schema compare tool after inferring types.
  • Document expected payload fields for reviewers who do not read OpenAPI.

Common mistakes to avoid

  • Treating inference as JSON Schema

    This shows types from one sample. Optional fields and unions need more samples or a schema validate pass.

FAQ

How are arrays handled?

Array item types come from the first element—same heuristic as the JSON → TypeScript generators.

Common search terms

Phrases people search for that match this tool. See the full long-tail keyword index.

  • infer json types online
  • json type tree from sample
  • json schema inference preview

Related utilities you can open in another tab—mostly client-side.