Json To Yup Schema
Type-Safe Yup Schema Synthesizer

JSON to Yup Validation Schema Generator

Transform JSON samples into type-safe Yup object validation schemas with yup.string(), yup.number(), yup.array(), and required rules.

100% Client-Side Privacy
Zero Server Transmission
Presets:
Indent:
Required Strategy:
Source JSON Payload
import * as yup from "yup";

// --- Inferred Nested Sub-Schemas ---
const OrderCustomerSchema = yup.object({
    id: yup.number().integer().required(),
    fullName: yup.string().required(),
    email: yup.string().email().required(),
    phone: yup.string().required(),
    tier: yup.string().required(),
    loyaltyPoints: yup.number().integer().required(),
  });
const OrderShippingAddressCoordinatesSchema = yup.object({
      latitude: yup.number().required(),
      longitude: yup.number().required(),
    });
const OrderShippingAddressSchema = yup.object({
    street: yup.string().required(),
    suite: yup.string().required(),
    city: yup.string().required(),
    state: yup.string().required(),
    postalCode: yup.string().required(),
    country: yup.string().required(),
    coordinates: OrderShippingAddressCoordinatesSchema,
  });
const OrderItemsItemSchema = yup.object({
    sku: yup.string().required(),
    title: yup.string().required(),
    quantity: yup.number().integer().required(),
    unitPrice: yup.number().required(),
    discount: yup.number().nullable(),
    tags: yup.array().of(yup.string().required()).required(),
    inStock: yup.boolean().required(),
  });
const OrderPaymentSummarySchema = yup.object({
    currency: yup.string().required(),
    subtotal: yup.number().integer().required(),
    tax: yup.number().required(),
    shippingFee: yup.number().integer().required(),
    grandTotal: yup.number().required(),
    transactionRef: yup.string().required(),
    status: yup.string().required(),
  });

// --- Root Yup Schema Definition ---
orderSchema = yup.object({
  orderId: yup.string().uuid().required(),
  orderNumber: yup.string().required(),
  createdAt: yup.string().datetime().required(),
  isFulfilled: yup.boolean().required(),
  customer: OrderCustomerSchema,
  shippingAddress: OrderShippingAddressSchema,
  items: yup.array().of(OrderItemsItemSchema).required(),
  paymentSummary: OrderPaymentSummarySchema,
}).required();

// --- Inferred TypeScript Types ---
OrderCustomerType = yup.InferType<typeof OrderCustomerSchema>;
OrderShippingAddressCoordinatesType = yup.InferType<typeof OrderShippingAddressCoordinatesSchema>;
OrderShippingAddressType = yup.InferType<typeof OrderShippingAddressSchema>;
OrderItemsItemType = yup.InferType<typeof OrderItemsItemSchema>;
OrderPaymentSummaryType = yup.InferType<typeof OrderPaymentSummarySchema>;
OrderType = yup.InferType<typeof orderSchema>;
Structural Complexity
Depth: 45 Sub-Schemas
Inferred Formats
3 Rules DetectedEmail, UUID, ISO, URL
TypeScript Exports
InferType ONsmart

100% Client-Side AST Inference

Deep JSON parsing and Yup schema synthesis run entirely in your local browser sandbox with zero network telemetry or remote execution.

Type-Safe Yup & TypeScript InferType

Generates recursive yup.object(), yup.array().of(), smart string formats, and type definitions ready for Formik and React Hook Form.

Smart Validation & Nullable Rules

Automatically detects emails, UUIDs, ISO datetime strings, URLs, and numeric constraints with configurable required and nullable strategies.

Technical Reference & Architecture Guide

JSON to Yup Validation Schema Generator — Reference Guide

Transform JSON samples into type-safe Yup object validation schemas with yup.string(), yup.number(), yup.array(), and required rules.

Key Parameters & Controls

Root Schema Namestring

Top-level identifier assigned to the exported Yup schema and its inferred TypeScript type definition.

Default: rootSchema
Extract Sub-Schemasboolean

Decomposes nested object hierarchies into standalone, reusable schema declarations named after their property keys.

Default: true
Smart Format Detectionboolean

Automatically detects RFC 5322 emails, UUIDs, URLs, and ISO 8601 datetimes, applying .email(), .uuid(), .url(), and .date().

Default: true
Required Strategyenum (all | optional | non-null)

Determines whether inferred properties are marked .required(), declared as .optional(), or required only when sample values are non-null.

Default: all
Disallow Unknown (.noUnknown)boolean

Appends .noUnknown() to object schemas to reject payloads containing unrecognized or unauthorized properties.

Default: false
Export TypeScript InferTypeboolean

Emits export type RootType = yup.InferType<typeof rootSchema>; to maintain compile-time type synchronization.

Default: true

Pro Tips & Best Practices

Use the generated schema directly

Use the generated schema directly in Formik via validationSchema={rootSchema} or in React Hook Form via useForm({ resolver: yupResolver(rootSchema) }) from @hookform/resolvers/yup.

By default

By default, Yup halts validation on the first error encountered. Pass schema.validate(data, { abortEarly: false }) to collect all invalid field errors at once into err.inner for complete form error messaging.

Maintain a single source

Maintain a single source of truth by avoiding duplicate interface files. Derive TypeScript contracts directly using export type FormData = yup.InferType<typeof rootSchema>; to ensure schema changes update compile-time types automatically.

Cleanse raw user input during

Cleanse raw user input during the validation phase by appending .transform((value) => (value === '' ? null : value)) or .trim() directly onto yup.string() rules to normalize empty strings and trim whitespace.

Common Gotchas & Troubleshooting

ValidationError only returns the first failure message instead of showing errors for all invalid form fields.

By default, Yup uses abortEarly: true. When calling schema.validate(data) or schema.validateSync(data), pass the configuration option { abortEarly: false } and inspect err.inner to retrieve the full list of errors.

Extra JSON properties disappear from the validated output or trigger unexpected validation failures.

Yup automatically strips undeclared keys unless configured otherwise. If you require strict rejection of undocumented keys, add .noUnknown(). To retain extra fields without schema declarations, configure stripUnknown: false in your validate options.

ISO 8601 string timestamps fail validation or are converted into invalid JavaScript Date objects.

yup.date() attempts native new Date() parsing which can fail on empty strings or malformed inputs. Use .nullable().transform((curr, orig) => orig === '' ? null : curr) or validate timestamp strings with yup.string().matches() for strict ISO 8601 patterns.

Frequently Asked Questions

What is the key difference between Yup and Zod for TypeScript projects?▼

While both perform schema validation, Zod was designed from scratch around TypeScript inference with immutable schema objects. Yup is historically deeply integrated into the React ecosystem (especially Formik and React Hook Form), features powerful contextual validations via .when(), and provides built-in casting/coercion mechanisms.

How do I connect the generated Yup schema with Formik or React Hook Form?▼

For Formik, pass the generated schema directly to the Formik component: <Formik validationSchema={rootSchema} ... />. For React Hook Form, install @hookform/resolvers and configure the hook: useForm({ resolver: yupResolver(rootSchema) }).

How does the generator handle heterogeneous elements in JSON arrays?▼

The generator inspects all array items across the sample. If items share identical property structures, it generates a unified yup.array().of(yup.object({...})). If elements contain mixed primitive types, it generates a permissive union or marks conflicting properties as optional.

Is my JSON payload or validation code uploaded to any external server?▼

No. All AST parsing, schema synthesis, and type deduction execute 100% locally within your browser sandbox via JavaScript. No payload data, cookies, or telemetry are ever transmitted across the network.

Can I extract TypeScript types from the generated Yup schema without writing manual interfaces?▼

Yes. Yup provides the built-in utility type yup.InferType<typeof schema>. By exporting type MyType = yup.InferType<typeof rootSchema>;, your TypeScript interfaces remain automatically in sync with runtime validation constraints.

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