Hex and Base64 Encoding

There are a few cases where it would be practical to encode and decode between different string and array buffer formats. The Deno standard library makes this easy.

The standard library provides hex and base64 encoding and decoding utilities

import * as base64 from "jsr:@std/encoding/base64";
import * as hex from "jsr:@std/encoding/hex";

We can easily encode a string or an array buffer into base64 using the base64.encode method.

const base64Encoded = base64.encode("somestringtoencode");
console.log(base64.encode(new Uint8Array([1, 32, 67, 120, 19])));

We can then decode base64 into a byte array using the decode method.

const base64Decoded = base64.decode(base64Encoded);

If we want to get the value as a string we can use the built-in TextDecoder. We will use these a lot so we can store them in variables to reuse them.

const textEncoder = new TextEncoder();
const textDecoder = new TextDecoder();
console.log(textDecoder.decode(base64Decoded));

To encode hex, we always use array buffers. To use a string as an input we can encode our text.

const arrayBuffer = textEncoder.encode("somestringtoencode");
const hexEncoded = hex.encode(arrayBuffer);
console.log(hexEncoded);

To read our hex values as a string, we can decode the buffer.

console.log(textDecoder.decode(hexEncoded));

We can convert back to a string by using the decode method.

const hexDecoded = hex.decode(hexEncoded);
console.log(textDecoder.decode(hexDecoded));

Run this example locally using the Deno CLI:

deno run https://docs.deno.com/by-example/hex-base64-encoding.ts