zod vs joi vs yup vs superstruct vs io-ts vs runtypes vs @conform-to/zod
JavaScript Validation Libraries Comparison
1 Year
zodjoiyupsuperstructio-tsruntypes@conform-to/zodSimilar Packages:
What's JavaScript Validation Libraries?

JavaScript validation libraries are essential tools that help developers ensure that the data being processed in their applications meets specific criteria. These libraries provide a way to define schemas for data validation, allowing for the enforcement of rules and constraints on data structures. They can be used in various contexts, such as form validation, API request validation, and data transformation, improving the reliability and robustness of applications by preventing invalid data from causing errors or unexpected behavior.

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zod31,140,90938,5141.63 MB5837 hours agoMIT
joi11,863,32621,111531 kB190a year agoBSD-3-Clause
yup7,261,22523,396260 kB2456 months agoMIT
superstruct2,734,6277,122182 kB98a year agoMIT
io-ts1,901,8446,778460 kB1646 months agoMIT
runtypes168,3132,656312 kB204 months agoMIT
@conform-to/zod110,1512,30891.8 kB9113 days agoMIT
Feature Comparison: zod vs joi vs yup vs superstruct vs io-ts vs runtypes vs @conform-to/zod

TypeScript Support

  • zod:

    Zod is built with TypeScript in mind, providing first-class support for type inference and ensuring that validation schemas align perfectly with TypeScript types.

  • joi:

    Joi has limited TypeScript support, which may require additional type definitions or workarounds to fully leverage TypeScript's capabilities in projects.

  • yup:

    Yup has basic TypeScript support, but developers may encounter challenges with type inference in more complex validation scenarios.

  • superstruct:

    superstruct supports TypeScript, allowing developers to define structures with type inference, but it may not be as comprehensive as other libraries in terms of type safety features.

  • io-ts:

    io-ts provides strong TypeScript integration, enabling developers to create runtime types that correspond to TypeScript types, ensuring consistency between compile-time and runtime validation.

  • runtypes:

    runtypes is designed for TypeScript, providing a straightforward way to define and validate types at runtime, ensuring type safety in applications.

  • @conform-to/zod:

    @conform-to/zod offers excellent TypeScript support, allowing developers to define schemas that automatically infer types, enhancing type safety across the application.

Validation Complexity

  • zod:

    Zod provides a clean API for defining validations, supporting both simple and complex scenarios while maintaining readability.

  • joi:

    Joi is highly versatile, supporting complex validation rules, custom validations, and conditional validations, making it ideal for applications with extensive validation needs.

  • yup:

    Yup supports complex validation scenarios, including asynchronous validations, making it suitable for form validation in modern web applications.

  • superstruct:

    superstruct offers a balance between simplicity and complexity, allowing for the composition of validation rules while maintaining a minimalistic approach.

  • io-ts:

    io-ts excels in handling complex validation scenarios, allowing for the creation of nested types and advanced validation rules, making it suitable for intricate data structures.

  • runtypes:

    runtypes focuses on simplicity, providing a clear API for defining types and validations, but may not support advanced validation scenarios as comprehensively as others.

  • @conform-to/zod:

    @conform-to/zod is designed for straightforward validations, making it easy to define simple schemas without unnecessary complexity.

Performance

  • zod:

    Zod is designed for high performance, providing fast validation checks while maintaining a clean and intuitive API.

  • joi:

    Joi's performance can vary based on the complexity of the validation schema; while it is powerful, it may not be the fastest option for simple validations.

  • yup:

    Yup is generally performant, but complex validation scenarios may introduce some latency, especially with asynchronous validations.

  • superstruct:

    superstruct is optimized for performance, allowing for fast validation checks with minimal overhead, making it a good choice for high-performance applications.

  • io-ts:

    io-ts has a performance overhead due to its runtime type checking capabilities, which may impact performance in high-frequency validation scenarios.

  • runtypes:

    runtypes is designed to be efficient, providing quick validation checks without significant overhead, making it suitable for performance-sensitive applications.

  • @conform-to/zod:

    @conform-to/zod is lightweight and optimized for performance, making it suitable for applications where speed is crucial.

Ease of Use

  • zod:

    Zod is known for its simplicity and ease of use, providing a clean API that allows developers to define schemas with minimal effort.

  • joi:

    Joi offers a rich API with extensive documentation, making it relatively easy to use, but its complexity can be overwhelming for beginners.

  • yup:

    Yup's fluent API is intuitive and easy to use, especially for developers familiar with form handling in React, making it a popular choice for client-side validation.

  • superstruct:

    superstruct is designed for simplicity, allowing developers to quickly define validation rules without extensive boilerplate code, making it easy to adopt.

  • io-ts:

    io-ts has a steeper learning curve due to its functional programming style, which may require more time for developers to become proficient.

  • runtypes:

    runtypes is straightforward to use, providing a clear and concise API for defining types and validations, making it accessible for developers of all skill levels.

  • @conform-to/zod:

    @conform-to/zod is user-friendly, with a simple API that makes it easy for developers to define and use validation schemas quickly.

Community and Ecosystem

  • zod:

    Zod is rapidly gaining traction due to its TypeScript-first approach and has a growing community, with increasing resources and support.

  • joi:

    Joi has a large and active community, with extensive documentation and numerous resources available, making it a reliable choice for developers.

  • yup:

    Yup has a strong community, especially in the React ecosystem, with a wealth of resources, plugins, and integrations available.

  • superstruct:

    superstruct is relatively new but has gained popularity for its performance and simplicity, with an emerging community and resources.

  • io-ts:

    io-ts has a dedicated community, particularly among TypeScript users, but its ecosystem may not be as rich as others in terms of plugins and extensions.

  • runtypes:

    runtypes has a smaller community compared to others, but it is well-documented and provides sufficient resources for developers.

  • @conform-to/zod:

    @conform-to/zod has a growing community and ecosystem, but it may not be as extensive as some of the more established libraries.

How to Choose: zod vs joi vs yup vs superstruct vs io-ts vs runtypes vs @conform-to/zod
  • zod:

    Opt for Zod if you are looking for a TypeScript-first validation library that emphasizes simplicity and developer experience. Zod provides a clean and intuitive API, making it easy to define schemas and perform validations while maintaining type safety.

  • joi:

    Opt for Joi if you need a robust and feature-rich validation library that supports a wide range of validation scenarios. Joi is highly customizable and allows for complex validations, making it a good choice for applications with extensive validation requirements, such as server-side validation in Node.js.

  • yup:

    Select Yup if you need a schema builder for value parsing and validation, especially in form handling scenarios. Yup's fluent API and built-in support for asynchronous validation make it an excellent choice for client-side form validation in React applications.

  • superstruct:

    Choose superstruct if you prefer a minimalistic approach to data validation with a focus on performance. It allows for easy composition of validation rules and is suitable for projects that require quick and efficient validation without extensive configuration.

  • io-ts:

    Select io-ts if you require runtime type checking and validation in TypeScript applications. It is particularly useful for validating external data sources, such as API responses, and can create complex type hierarchies, making it suitable for applications with intricate data structures.

  • runtypes:

    Use runtypes if you want a library that focuses on runtime type checking with a simple API. It is particularly useful for validating data structures in TypeScript, providing a straightforward way to ensure data integrity without the overhead of more complex libraries.

  • @conform-to/zod:

    Choose @conform-to/zod if you need a lightweight validation library that integrates seamlessly with TypeScript, providing type inference and a simple API for defining schemas. It's ideal for projects where type safety is a priority and you want to leverage TypeScript's capabilities.

README for zod

Zod logo

Zod

TypeScript-first schema validation with static type inference
by @colinhacks


Zod CI status License npm discord server stars

Docs   •   Discord   •   𝕏   •   Bluesky


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Read the docs →



What is Zod?

Zod is a TypeScript-first validation library. Define a schema and parse some data with it. You'll get back a strongly typed, validated result.

import { z } from "zod/v4";

const User = z.object({
  name: z.string(),
});

// some untrusted data...
const input = {
  /* stuff */
};

// the parsed result is validated and type safe!
const data = User.parse(input);

// so you can use it with confidence :)
console.log(data.name);

Features

  • Zero external dependencies
  • Works in Node.js and all modern browsers
  • Tiny: 2kb core bundle (gzipped)
  • Immutable API: methods return a new instance
  • Concise interface
  • Works with TypeScript and plain JS
  • Built-in JSON Schema conversion
  • Extensive ecosystem

Installation

npm install zod

Basic usage

Before you can do anything else, you need to define a schema. For the purposes of this guide, we'll use a simple object schema.

import { z } from "zod/v4";

const Player = z.object({
  username: z.string(),
  xp: z.number(),
});

Parsing data

Given any Zod schema, use .parse to validate an input. If it's valid, Zod returns a strongly-typed deep clone of the input.

Player.parse({ username: "billie", xp: 100 });
// => returns { username: "billie", xp: 100 }

Note — If your schema uses certain asynchronous APIs like async refinements or transforms, you'll need to use the .parseAsync() method instead.

const schema = z.string().refine(async (val) => val.length <= 8);

await schema.parseAsync("hello");
// => "hello"

Handling errors

When validation fails, the .parse() method will throw a ZodError instance with granular information about the validation issues.

try {
  Player.parse({ username: 42, xp: "100" });
} catch (err) {
  if (err instanceof z.ZodError) {
    err.issues;
    /* [
      {
        expected: 'string',
        code: 'invalid_type',
        path: [ 'username' ],
        message: 'Invalid input: expected string'
      },
      {
        expected: 'number',
        code: 'invalid_type',
        path: [ 'xp' ],
        message: 'Invalid input: expected number'
      }
    ] */
  }
}

To avoid a try/catch block, you can use the .safeParse() method to get back a plain result object containing either the successfully parsed data or a ZodError. The result type is a discriminated union, so you can handle both cases conveniently.

const result = Player.safeParse({ username: 42, xp: "100" });
if (!result.success) {
  result.error; // ZodError instance
} else {
  result.data; // { username: string; xp: number }
}

Note — If your schema uses certain asynchronous APIs like async refinements or transforms, you'll need to use the .safeParseAsync() method instead.

const schema = z.string().refine(async (val) => val.length <= 8);

await schema.safeParseAsync("hello");
// => { success: true; data: "hello" }

Inferring types

Zod infers a static type from your schema definitions. You can extract this type with the z.infer<> utility and use it however you like.

const Player = z.object({
  username: z.string(),
  xp: z.number(),
});

// extract the inferred type
type Player = z.infer<typeof Player>;

// use it in your code
const player: Player = { username: "billie", xp: 100 };

In some cases, the input & output types of a schema can diverge. For instance, the .transform() API can convert the input from one type to another. In these cases, you can extract the input and output types independently:

const mySchema = z.string().transform((val) => val.length);

type MySchemaIn = z.input<typeof mySchema>;
// => string

type MySchemaOut = z.output<typeof mySchema>; // equivalent to z.infer<typeof mySchema>
// number