Base32 in pure JavaScript

base32.js

const BASE32_ALPHABET = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ234567';

function encodeBase32(input) {
    const buffer = Buffer.from(input);
    let bits = 0;
    let value = 0;
    let output = '';

    for (let i = 0; i < buffer.length; i++) {
        value = (value << 8) | buffer[i];
        bits += 8;
        while (bits >= 5) {
            output += BASE32_ALPHABET[(value >>> (bits - 5)) & 31];
            bits -= 5;
        }
    }

    if (bits > 0) {
        output += BASE32_ALPHABET[(value << (5 - bits)) & 31];
    }

    while (output.length % 8) {
        output += '=';
    }

    return output;
}

const encoded = encodeBase32('Hello');
// JBSWY3DP
console.log(encoded);