TypeScript to JSON Schema Converter
Paste a TypeScript interface or type to instantly generate a matching draft-07 JSON Schema document. Free online developer tool.
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JSON Schema
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Free TypeScript to JSON Schema Converter
Paste a TypeScript interface or type to instantly generate a matching draft-07 JSON Schema document, with required and nested properties filled in automatically.
How to Use It
Paste TypeScript source into the input box, or click "Load Example." The tool parses the first top-level interface or type declaration with the TypeScript compiler, resolving any other top-level interfaces it references by name, and emits a JSON Schemaobject definition for every level, listing every non-optional property underrequired and describing arrays with an items schema.
Example
Given an Address interface with an optional zip field and a User interface referencing it, the tool emits a schema whose address property is a nested object schema with "required": ["city"], and whose tags property is{ "type": "array", "items": { "type": "string" } }.
Common Use Cases
- Generating a validation schema for an API payload already typed in TypeScript.
- Documenting a TypeScript interface as a portable, language-agnostic JSON Schema.
- Feeding a JSON Schema into form-generation or OpenAPI tooling from an existing type.
FAQs
Does this support more than one interface at a time?
The tool converts the first top-level interface or type in your input as the root schema. If that root type references other top-level interfaces from the same file by name (likeaddress: Address), those are resolved and inlined as nested schemas automatically — but interfaces that aren't referenced from the root are ignored.
How are optional and nullable fields represented?
An optional property (zip?: string) is simply left out of the schema'srequired array. A nullable property (a union with null) gets itstype turned into an array like ["string", "null"], matching JSON Schema draft-07 conventions.
Is my TypeScript uploaded anywhere?
No — parsing and schema generation happen entirely client-side in your browser, using the TypeScript compiler loaded on demand. Nothing you paste is sent to a server.