Skip to content
ToolsOnDuty - free online tools
Developer Tools

JSON Schema Generator

Infer a draft 2020-12 JSON Schema from the types and structure of an example JSON value.

Free browser toolRuns in your browserNo sign-up
Schema inference workspace

Infer a draft 2020-12 schema from representative JSON

Map the observed object, array and primitive structure into a readable JSON Schema starting point for validation and documentation.

Infer schema

mode

75 B

input size

434 B

output size

Representative JSON

75 characters

Inferred JSON Schema

434 characters

Inference only describes types observed in this sample. Add business constraints, required-field decisions, formats and mixed-array rules before production use.

Private by design. Input is processed inside this browser tab and is not sent to ToolsOnDuty.

About the JSON Schema Generator

JSON Schema Generator is a focused browser-based utility. Infer a draft 2020-12 JSON Schema from the types and structure of an example JSON value.

The calculation runs locally in your browser, so the supplied value is not uploaded to ToolsOnDuty. The same capability is also available through the authenticated developer API.

Key features

  • Fast local processing with explicit validation
  • Copy-ready structured result
  • No account, upload or paid data provider required

How to use

  1. 1Enter representative valid JSON.
  2. 2Choose any available conversion or formatting options.
  3. 3Run the tool and review an inferred JSON Schema.

Examples

JSON Schema Generator example
Input: representative valid JSON
Output: an inferred JSON Schema

Frequently asked questions

Is my input uploaded?
No. This website tool runs in your browser. Only the optional public API version sends input to the authenticated API route.
Can I use this in an application?
Yes. The Developers documentation lists the authenticated endpoint, request parameters and response example.
Should I verify the result?
Yes. Deterministic tools are designed for repeatable results, but format-specific or heuristic output should still be checked for your use case.

Continue your workflow

Open a related tool to prepare your files or refine the finished result.