JSON Schema Generator

The JSON Schema Generator inspects one or more example JSON documents and infers a basic JSON Schema that describes their structure, saving you from writing the schema by hand. It walks every property in your sample, records whether each value is a string, number, integer, boolean, object, array, or null, and assembles a schema with the appropriate type declarations and nested property definitions. The result is a draft contract you can use to validate future payloads, document an API, or generate types in your codebase.

The tool works by reading your example and mapping each field to its corresponding schema type, descending recursively into nested objects and inferring the item type for arrays based on the elements it sees. Because it generates from real data, the schema reflects exactly what your sample contains, which is the fastest way to bootstrap a contract for an endpoint you do not control. It is a starting point rather than a final specification, so you will typically tighten it afterward by marking which fields are required, adding formats, or constraining value ranges.

Common use cases include creating validation schemas for incoming webhook payloads, documenting the shape of an API response for teammates, scaffolding request validators, and producing a baseline that tools can turn into TypeScript interfaces or form definitions. Developers reach for it whenever they have a representative example but no formal schema yet. It pairs naturally with the JSON Tree Viewer for first understanding the data's shape, and the generated schema can later feed validators that enforce the contract at runtime.

A practical tip is to feed the generator the richest, most complete example you have, ideally one where every optional field is populated, so the inferred schema captures all possible properties. Remember that inference cannot know which fields are truly required or what business rules apply, so review the output and add constraints like required arrays, string formats, enums, and minimum or maximum values before treating it as authoritative.