JSON to Zod Schema Generator
💡 Pro Tip: Verify Before You Deploy
Don’t just copy and paste. You can test this schema instantly in our new Validator Playground to ensure it handles your API’s edge cases correctly.
Why Standard TypeScript Interfaces Aren’t Enough
If you are a modern web developer, you know the struggle: You define a perfect interface User, but when you fetch data from an external API, there is no guarantee the runtime data actually matches your static types. TypeScript types vanish at compile time, leaving your application vulnerable to **runtime errors** and unexpected crashes.
This is where Zod comes in. Zod is a TypeScript-first schema declaration and validation library. By converting your raw **JSON to Zod schemas**, you get:
- Runtime Validation: Your app will throw a descriptive error (via
safeParse) if the API contract is violated. - Automatic Type Inference: Generate strict TypeScript types (
z.infer) directly from your schema, keeping your code DRY (Don’t Repeat Yourself). - Data Coercion: Automatically fix messy data types (like turning string numbers into actual numbers) before they reach your UI.
"price": "19.99"). Zod will handle the transformation for you.How to Handle Zod Optional Fields
One of the most common challenges in schema validation is handling partial data, especially for PATCH requests or complex forms. By default, Zod is strict—if a field is missing, validation fails.
Our generator solves this with the “Make All Fields Optional” toggle. This automatically appends the .optional() method to every key in your object. This is critical when you need to validate a form that might not be fully filled out yet.
Generating TypeScript Types from Zod
You don’t need to manually write a separate TypeScript interface. The true power of Zod lies in Type Inference. Our tool automatically generates the export line for you:
This creates a single source of truth. If you update your Zod schema to add a new field, your TypeScript types update automatically across your entire project. No more syncing two separate files!
Real-World Use Cases
1. API Response Validation: External APIs are unpredictable. Instead of manually writing interfaces, paste the API response JSON here. Use the generated schema to validate incoming data using z.safeParse().
2. React Hook Form Validation: Zod integrates perfectly with React Hook Form via standard resolvers. Paste your default form values (as JSON), generate the schema, and you have instant client-side validation logic.
Frequently Asked Questions
Does this support nested arrays and objects?
Yes. The tool recursively detects arrays of objects or primitives. If you paste a list of users, it intelligently generates a z.array(z.object({...})) schema structure.
What is the difference between z.string() and z.coerce.string()?
z.string() is strict; it throws an error if the input is a number. Zod Coercion (z.coerce.string()) is loose; it will take a number (like 123) and convert it into a string ("123"). Use coercion when you can’t fully trust the data types coming from your backend.