JSON Schema Generator
Generate a JSON Schema from a sample JSON document, with a toggle for the required-fields default.
Processed locally in your browser. Nothing you enter is uploaded or stored.
- Produces a valid draft-07 skeleton with types, properties and nesting.
- Saves the tedious first pass of a schema you'll then tighten.
- A "Mark all fields as required" toggle skips the manual cleanup of removing required constraints one by one when most fields are actually optional.
- Runs in your browser; the sample isn't uploaded.
Why this is private
- Processed locally in your browser. Nothing you enter is uploaded or stored.
- Open your browser's DevTools → Network tab while using this tool — you won't see a request carrying your input, because it never leaves your device.
- Nothing you enter is uploaded to a server or shared with us — the processing happens entirely on your device.
Overview
Infers a draft-07 JSON Schema from a sample JSON document — a starting point to refine, not a full schema authoring tool.
How to use it
- 1Paste a representative JSON sample.
- 2Leave "Mark all fields as required" on for a strict schema, or turn it off if most fields are actually optional.
- 3Copy the generated schema and adjust further constraints (formats, min/max, enums) by hand as needed.
Tips
- The generator can't know which fields are actually optional from a single example — if most fields in your sample are optional, turn off "Mark all fields as required" instead of removing them from the output by hand one at a time.
Frequently asked questions
What people use it for
Start a schema for request validationGenerate the structure, then add `format` and range constraints.
Describe a config file's shapeProduce a schema an editor can use for autocomplete and validation.
Pair with the JSON Schema ValidatorGenerate here, refine, then validate real payloads against it.
Document an API contractA schema is a precise, machine-readable description of the payload.
Related guides
- How to read JSON with a tree viewerA tree viewer turns a wall of brackets into a structure you can expand, search and copy paths from. Here's how to use one effectively.
- JSON parse errors explained: 'Unexpected token', 'Expected comma or brace', and the restWhat each common JSON error message actually means, the usual cause, and how to find the spot fast using line and column.
- How to format JSON (and actually understand the errors)JSON looks like a JavaScript object but follows stricter rules. Here's what those rules are and how to read the errors when they're broken.
Related tools
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JSON Schema Generator