minivalid.js

Tiny, dependency-free validation utilities for JavaScript.

minivalid.js provides simple, composable validation functions that can be combined into a lightweight validation pipeline. It is designed for small projects that do not need a full schema validation framework.

Installation

npm install minivalid

Usage

import {
  validate,
  required,
  validateEmail,
  validatePassword,
  min,
  max,
  isNumber
} from "minivalid";

Basic example

const result = validate("[email protected]", [
  required,
  validateEmail
]);

console.log(result);

// { isValid: true, error: null }

Password validation

const result = validate("P@ssw0rd123", [
  required,
  validatePassword
]);

console.log(result);
// { isValid: true, error: null }

String validation rules

const result = validate("hello", [
  required,
  min(3),
  max(10)
]);

console.log(result);
// { isValid: true, error: null }

Number validation

const result = validate(42, [
  required,
  isNumber
]);

console.log(result);
// { isValid: true, error: null }

How it works

Each validator is a function that returns:

(value) => ({
  isValid: boolean,
  error: string | null
});

The validate function runs validators in order and stops at the first failure.

API
validate(value, validators)

Runs an array of validator functions against a value.

Returns:

{
  isValid: boolean,
  error: string | null
}

Built-in validators

required(value)
validateEmail(value)
validatePassword(value)
min(length)
max(length)
isNumber(value)

Philosophy

minivalid.js is intentionally minimal.

It does not include:

schema validation async validation form state management external dependencies

It focuses only on small reusable validation primitives.

License

MIT