How to generate zod-ready typescript interfaces from json
- Step 1Generate the TypeScript interface from JSON — Paste the JSON and convert. Review the generated interface — it shows the full type structure including nested objects and array types.
- Step 2Write the Zod schema following the interface — For each property in the interface, add the corresponding Zod type: string →’ z.string(), number →’ z.number(), boolean →’ z.boolean(), nested interface →’ z.object({}), string[] →’ z.array(z.string()).
- Step 3Add validation constraints — Enhance the Zod schema with constraints the interface cannot express: z.string().email(), z.number().min(0).max(100), z.string().uuid(), z.enum(['active', 'inactive']). These constraints are the primary value of Zod over a bare TypeScript type.
- Step 4Derive the TypeScript type from the Zod schema — After writing the Zod schema, derive the TypeScript type from it: type User = z.infer<typeof UserSchema>. This replaces the hand-generated interface with a type that is always in sync with the schema.
Frequently asked questions
Should I write the TypeScript interface first or the Zod schema first?+
Write the Zod schema first and derive the TypeScript type with z.infer. This ensures the runtime validation and the static type are always identical. This tool is useful as an intermediate step when starting from JSON data — generate the interface to understand the shape, then write the Zod schema from that understanding.
How do I handle JSON null values in Zod?+
JSON null values in the sample produce type: null in the generated interface. In Zod, use z.nullable(): z.string().nullable() for a field that is string or null. For optional-and-nullable: z.string().nullable().optional().
Is the JSON data transmitted to JAD Apps?+
No. Conversion runs entirely in your browser. JSON data is never transmitted to JAD Apps servers.
Privacy first
Conversion runs locally in your browser. No file is uploaded — only metadata counters are saved for signed-in dashboard stats.