The Uint8Array.fromHex() static method creates a new Uint8Array object from a hexadecimal string.

This method parses the string into a byte array. To convert the string into a single number, use the parseInt() function with radix set to 16 instead.

Syntax

Uint8Array.fromHex(string)

Parameters

string

A hexadecimal string encoding bytes to convert to a Uint8Array. The string must:

• Have an even number of characters because two characters encode one byte.
• Only contain characters in the hexadecimal alphabet, which includes 0–9 and A–F (case-insensitive).
• Not contain whitespace (unlike Uint8Array.prototype.setFromBase64()).

Return value

A new Uint8Array object containing the decoded bytes from the hexadecimal string.

Exceptions

SyntaxError

Thrown if the input string contains characters outside the hex alphabet, or its length is odd.

TypeError

Thrown if the input string is not a string.

Examples

Decoding a hexadecimal string

This example decodes a hexadecimal string into a Uint8Array.

const hexString = "cafed00d";
const bytes = Uint8Array.fromHex(hexString);
console.log(bytes); // Uint8Array [ 202, 254, 208, 13 ]

Uppercase characters are also supported:

const hexString = "CAFEd00d";
const bytes = Uint8Array.fromHex(hexString);
console.log(bytes); // Uint8Array [ 202, 254, 208, 13 ]

Specifications

Browser compatibility

See also

• Polyfill of Uint8Array.fromHex in core-js
• es-shims polyfill of Uint8Array.fromHex
• Uint8Array
• Uint8Array.prototype.setFromHex()
• Uint8Array.prototype.toHex()
• parseInt()