JSON Schema Generator
Infer a JSON Schema from a sample JSON document, with draft selection and required policies.
Max depth
Total properties
Status
Why use this tool
01Paste a JSON sample and get a draft-2020-12 or draft-07 schema with detected string formats, merged array items, and configurable required handling.
JSON Schema Generator infers a schema from a sample JSON document so you can validate future payloads, generate TypeScript, or document APIs.
It merges array element schemas, detects common string formats (date-time, email, uri, uuid), and supports draft 2020-12 and draft-07.
How to use
02Quick checks before you copy
03Confirm the input is the format you intended.
Scan the result before using it in a document, URL, config, or message.
Copy only the output you need.
Tips & Tricks
- 01Validate before copying
If the input parser reports an error, fix the source value first instead of copying a partial result into code, config, or documentation.
- 02Keep secrets local
The tool runs in your browser, but you should still avoid pasting long-lived production secrets into any shared or screen-recorded session.
FAQ
04What does the smart required policy do?
For arrays, every element schema is merged and only the keys present in every element stay required. For single objects it behaves like 'all required'.
Does it detect string formats?
Yes. Date, date-time, email, uri, and uuid formats are inferred from sample values.
Is my JSON sent anywhere?
No. Inference runs entirely in this tab.
Related tools
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Generate TypeScript interfaces from a JSON sample — nested types, arrays, optional keys inferred.