Uint8Array Base64 and Hex Conversion Utilities

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Available Methods

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Static Methods

• Uint8Array.fromBase64(string): Creates a new Uint8Array from a base64-encoded string
• Uint8Array.fromHex(string): Creates a new Uint8Array from a hexadecimal string

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Instance Methods

• Uint8Array.prototype.toBase64(): Converts the Uint8Array to a base64-encoded string
• Uint8Array.prototype.toHex(): Converts the Uint8Array to a hexadecimal string
• Uint8Array.prototype.setFromBase64(string): Populates the Uint8Array with data from a base64-encoded string
• Uint8Array.prototype.setFromHex(string): Populates the Uint8Array with data from a hexadecimal string

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Static Methods

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Uint8Array.fromBase64(string)

static fromBase64(base64String: string): Uint8Array

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Parameters:

• base64String: A string containing base64-encoded data.

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Returns:

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Notes:

• Only the default implementation is supported - there is no support for options such as base64url alphabet or lastChunkHandling. The standard base64 alphabet and loose lastChunkHandling are currently the only supported modes of operation.

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Example:

const data = Uint8Array.fromBase64('SGVsbG8gV29ybGQ=');
console.log(data); // Uint8Array representing "Hello World"

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Uint8Array.fromHex(string)

static fromHex(hexString: string): Uint8Array

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Parameters:

• hexString: A string containing hexadecimal data. Must have an even length and contain only valid hexadecimal characters (0-9, A-F, a-f).

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Returns:

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Example:

const data = Uint8Array.fromHex('48656c6c6f20576f726c64');
console.log(data); // Uint8Array representing "Hello World"

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Instance Methods

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Uint8Array.prototype.toBase64()

toBase64(): string

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Returns:

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Notes:

• Only the default implementation is supported - there is no support for options such as base64url alphabet or omitPadding. The standard base64 alphabet is used and padding is always included (equivalent to omitPadding: false).

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Example:

const array = new Uint8Array([
  72, 101, 108, 108, 111, 32, 87, 111, 114, 108, 100
]);
const base64 = array.toBase64();
console.log(base64); // "SGVsbG8gV29ybGQ="

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Uint8Array.prototype.toHex()

toHex(): string

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Returns:

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Example:

const array = new Uint8Array([
  72, 101, 108, 108, 111, 32, 87, 111, 114, 108, 100
]);
const hex = array.toHex();
console.log(hex); // "48656c6c6f20576f726c64"

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Uint8Array.prototype.setFromBase64(string)

setFromBase64(base64String: string): {read: number, written: number}

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Parameters:

• base64String: A string containing base64-encoded data.

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Returns:

• read: Number of characters read from the input string
• written: Number of bytes written to the Uint8Array

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Notes:

• Only the default implementation is supported - there is no support for options such as base64url alphabet or lastChunkHandling. The standard base64 alphabet and loose lastChunkHandling are currently the only supported modes of operation.

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Example:

const array = new Uint8Array(20);
const result = array.setFromBase64('SGVsbG8gV29ybGQ=');
console.log(result); // { read: 16, written: 11 }
console.log(array); // Uint8Array containing "Hello World" followed by zeros

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Uint8Array.prototype.setFromHex(string)

setFromHex(hexString: string): {read: number, written: number}

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Parameters:

• hexString: A string containing hexadecimal data. Must have an even length and contain only valid hexadecimal characters (0-9, A-F, a-f).

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Returns:

• read: Number of characters read from the input string
• written: Number of bytes written to the Uint8Array

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Example:

const array = new Uint8Array(20);
const result = array.setFromHex('48656c6c6f20576f726c64');
console.log(result); // { read: 22, written: 11 }
console.log(array); // Uint8Array containing "Hello World" followed by zeros

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Notes

• These methods are optimized for performance and use native implementations where available.
• When working with large binary data, these methods are significantly more efficient than manual conversion approaches.
• These methods are compatible with the standard JavaScript Uint8Array API and don’t interfere with existing functionality.