Uint8ClampedArray

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.

The Uint8ClampedArray typed array represents an array of 8-bit unsigned integers clamped to 0–255. The contents are initialized to 0 unless initialization data is explicitly provided. Once established, you can reference elements in the array using the object's methods, or using standard array index syntax (that is, using bracket notation).

Uint8ClampedArray is a subclass of the hidden TypedArray class.

Constructor

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Uint8ClampedArray()

Creates a new Uint8ClampedArray object.

Static properties

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Also inherits static properties from its parent TypedArray.

Uint8ClampedArray.BYTES_PER_ELEMENT

Returns a number value of the element size. 1 in the case of Uint8ClampedArray.

Static methods

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Inherits static methods from its parent TypedArray.

Instance properties

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Also inherits instance properties from its parent TypedArray.

These properties are defined on Uint8ClampedArray.prototype and shared by all Uint8ClampedArray instances.

Uint8ClampedArray.prototype.BYTES_PER_ELEMENT

Returns a number value of the element size. 1 in the case of a Uint8ClampedArray.

Uint8ClampedArray.prototype.constructor

The constructor function that created the instance object. For Uint8ClampedArray instances, the initial value is the Uint8ClampedArray constructor.

Instance methods

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Inherits instance methods from its parent TypedArray.

Examples

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Different ways to create a Uint8ClampedArray

js
// From a length
const uint8c = new Uint8ClampedArray(2);
uint8c[0] = 42;
uint8c[1] = 1337;
console.log(uint8c[0]); // 42
console.log(uint8c[1]); // 255 (clamped)
console.log(uint8c.length); // 2
console.log(uint8c.BYTES_PER_ELEMENT); // 1

// From an array
const x = new Uint8ClampedArray([21, 31]);
console.log(x[1]); // 31

// From another TypedArray
const y = new Uint8ClampedArray(x);
console.log(y[0]); // 21

// From an ArrayBuffer
const buffer = new ArrayBuffer(8);
const z = new Uint8ClampedArray(buffer, 1, 4);
console.log(z.byteOffset); // 1

// From an iterable
const iterable = (function* () {
  yield* [1, 2, 3];
})();
const uint8cFromIterable = new Uint8ClampedArray(iterable);
console.log(uint8cFromIterable);
// Uint8ClampedArray [1, 2, 3]

Specifications

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Specification
ECMAScript® 2026 Language Specification
# table-49

Browser compatibility

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See also

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