For AI agents: the complete documentation index is available at /llms.txt, the full documentation bundle is available at /llms-full.txt, and this page is available as Markdown at /reference/predicate/isPlainObject.md.
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    isPlainObject es-toolkit

    Checks if a value is a plain object.

    const result = isPlainObject(value);

    Usage

    isPlainObject(value)

    Use isPlainObject when you want to check if a value is a plain object. A plain object is an object created with an object literal ({}) or the Object constructor. Class instances, arrays, or other special objects are not plain objects.

    import { isPlainObject } from 'es-toolkit/predicate';

// Plain objects
console.log(isPlainObject({})); // true
console.log(isPlainObject({ name: 'John', age: 30 })); // true
console.log(isPlainObject(Object.create(null))); // true
console.log(isPlainObject(new Object())); // true

// Non-plain objects
console.log(isPlainObject([])); // false (array)
console.log(isPlainObject(new Date())); // false (Date object)
console.log(isPlainObject(new Set())); // false (Set object)
console.log(isPlainObject(new Map())); // false (Map object)
console.log(isPlainObject(null)); // false (null)
console.log(isPlainObject(42)); // false (number)
console.log(isPlainObject('hello')); // false (string)

// Class instances
class MyClass {}
console.log(isPlainObject(new MyClass())); // false

    It's useful when serializing data or validating configuration objects.

    function processConfig(config: unknown) {
  if (isPlainObject(config)) {
    // config is now narrowed to Record<PropertyKey, any>
    console.log('Valid configuration object');
    Object.keys(config).forEach(key => {
      console.log(`${key}: ${config[key]}`);
    });
  } else {
    throw new Error('Configuration must be a plain object');
  }
}

    Parameters

    valueunknownrequired

    The value to check if it's a plain object.

    Returns

    Returns true if the value is a plain object, false otherwise.

    value is Record<PropertyKey, any>
    Source: es-toolkit

    Re-exported verbatim from es-toolkit. Implementation, edge cases, and performance behavior are owned upstream. This page mirrors the documentation at the pinned version; the linked source is authoritative.