What is the difference between Yup and Zod?

Yup and Zod are libraries for data validation and typing in JavaScript/TypeScript, but they have differences:

• Yup is an older and more popular library, focused on schema validation with a declarative API. It integrates well with React and forms (e.g., Formik). It supports asynchronous validation.

• Zod is a more modern library, originally designed with TypeScript in mind. It allows automatic inference of TypeScript types from schemas, simplifying typing. Validation is synchronous and very fast.

The main difference is that Zod is better suited for TypeScript projects due to its tight integration with types, while Yup is more versatile and supports asynchronous checks.

Example of a validation schema with Zod:

import { z } from 'zod';

const schema = z.object({
  username: z.string().min(3),
  age: z.number().int().positive(),
});

// Type is automatically inferred from the schema
type User = z.infer<typeof schema>;

const result = schema.safeParse({ username: 'Tom', age: 25 });
if (!result.success) {
  console.log(result.error.errors);
}