Uint8Array.fromHex()

The Uint8Array.fromHex() static method creates a new {{jsxref("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 {{jsxref("Global_Objects/parseInt", "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 {{jsxref("Uint8Array.prototype.setFromBase64()")}}).

Return value#

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

Exceptions#

• {{jsxref("SyntaxError")}}
• : Thrown if the input string contains characters outside the hex alphabet, or its length is odd.
• {{jsxref("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#

{{Specifications}}

Browser compatibility#

{{Compat}}

See also#

• Polyfill of Uint8Array.fromHex in core-js
• es-shims polyfill of Uint8Array.fromHex
• {{jsxref("Uint8Array")}}
• {{jsxref("Uint8Array.prototype.setFromHex()")}}
• {{jsxref("Uint8Array.prototype.toHex()")}}
• {{jsxref("Global_Objects/parseInt", "parseInt()")}}