Uint8Array.fromHex()

Baseline 2025

Newly available

Since September 2025, this feature works across the latest devices and browser versions. This feature might not work in older devices or browsers.

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.

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

Uppercase characters are also supported:

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

Specifications

Specification

ECMAScript® 2027 Language Specification
# sec-uint8array.fromhex

Browser compatibility

Enable JavaScript to view this browser compatibility table.

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Standard built-in objects
Uint8Array
Constructor
1. Uint8Array()
Static methods
1. fromBase64()
2. fromHex()
Instance methods
1. setFromBase64()
2. setFromHex()
3. toBase64()
4. toHex()
Inheritance
TypedArray
Static methods
1. from()
2. of()
Static properties
1. BYTES_PER_ELEMENT
2. [Symbol.species]
Instance methods
1. at()
2. copyWithin()
3. entries()
4. every()
5. fill()
6. filter()
7. find()
8. findIndex()
9. findLast()
10. findLastIndex()
11. forEach()
12. includes()
13. indexOf()
14. join()
15. keys()
16. lastIndexOf()
17. map()
18. reduce()
19. reduceRight()
20. reverse()
21. set()
22. slice()
23. some()
24. sort()
25. subarray()
26. toLocaleString()
27. toReversed()
28. toSorted()
29. toString()
30. values()
31. with()
32. [Symbol.iterator]()
Instance properties
1. buffer
2. byteLength
3. byteOffset
4. length
Object/Function
Static methods
1. apply()
2. bind()
3. call()
4. toString()
5. [Symbol.hasInstance]()
Static properties
1. displayName
2. length
3. name
4. prototype
5. arguments
6. caller
Instance methods
1. __defineGetter__()
2. __defineSetter__()
3. __lookupGetter__()
4. __lookupSetter__()
5. hasOwnProperty()
6. isPrototypeOf()
7. propertyIsEnumerable()
8. toLocaleString()
9. toString()
10. valueOf()
Instance properties
1. __proto__
2. constructor
Related pages
BigInt64Array
BigUint64Array
Float16Array
Float32Array
Float64Array
Int8Array
Int16Array
Int32Array
Uint8ClampedArray
Uint16Array
Uint32Array