Base62 Encoder & Decoder

Decode Base62

About Base62

What is Base62?

This Base62 variant treats bytes as a big-endian integer and writes it with the fixed alphabet 0-9A-Za-z. Leading zero bytes become leading 0 characters so decoding reconstructs the original byte sequence.

Why use Base62?

Use Base62 for compact, punctuation-free identifiers in URLs or databases. Base62 has no universal standard, so alphabet order and leading-zero rules must match; this reversible encoding is neither a hash nor encryption and includes no checksum.

Base62 in JavaScript

// npm install base-x
import basex from 'base-x';

const base62 = basex('0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz');

const encoded = base62.encode(Buffer.from('Hello'));
console.log(encoded);
// Output: 5TP3P3v

const decoded = Buffer.from(base62.decode('5TP3P3v')).toString('utf8');
console.log(decoded);
// Output: Hello
				

Base62 in Go

package main

import (
	"fmt"

	"github.com/eknkc/basex"
)

func main() {
	base62, _ := basex.NewEncoding("0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz")

	encoded := base62.Encode([]byte("Hello"))
	fmt.Println(encoded)
	// Output: 5TP3P3v

	decoded, _ := base62.Decode(encoded)
	fmt.Println(string(decoded))
	// Output: Hello
}
				

Base62 in PHP

<?php
// composer require tuupola/base62
require 'vendor/autoload.php';

$base62 = new Tuupola\Base62;

$encoded = $base62->encode("Hello");
echo $encoded . "\n";

$decoded = $base62->decode($encoded);
echo $decoded . "\n";
// Output: Hello