Base62 PHP Library

Install the library using Composer. The current branch requires PHP 7.1 or higher. For older environments (PHP 5.6 or 7.0), you must specify the 1.x branch.

# For PHP 7.1+
$ composer require tuupola/base62

# For PHP 5.6 or 7.0
$ composer require "tuupola/base62:^1.0"

You can customize the Base62 character set by passing a characters key in the constructor options. The library provides two built-in constants:

• Base62::GMP: 0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz (Default)
• Base62::INVERTED: 0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ

use Tuupola\Base62;

// Use the inverted character set
$inverted = new Base62(["characters" => Base62::INVERTED]);
print $inverted->encode("Hello world!"); // t8DGCJrgUyuUEwHT

// Use a custom character set
$custom = new Base62(["characters" => "ABC...[62 unique chars]..."]);

Use the Tuupola\Base62 class to encode and decode arbitrary binary data (strings). The library automatically uses the GMP extension if available for better performance, falling back to a pure PHP implementation if GMP is missing.

$base62 = new Tuupola\Base62();

$encoded = $base62->encode(random_bytes(128));
$decoded = $base62->decode($encoded);

When working specifically with integers, use encodeInteger() and decodeInteger().

Important: Encoding a string representation of a number (e.g., encode("987654321")) yields a different result than encoding the integer itself (e.g., encodeInteger(987654321)).

$base62 = new Tuupola\Base62();

$integer = $base62->encodeInteger(987654321); // 14q60P
print $base62->decodeInteger("14q60P"); // 987654321

// Note the difference:
$stringResult = $base62->encode("987654321"); // KHc6iHtXW3iD

If you are certain the GMP extension is installed, you can bypass the automatic detection and use Tuupola\Base62\GmpEncoder directly for maximum performance.

if (function_exists("gmp_init")) {
    $base62 = new Tuupola\Base62\GmpEncoder();
    $encoded = $base62->encode("Hello world!");
} else {
    /* Handle error... */
}

If you prefer not to instantiate the class, you can use Tuupola\Base62Proxy to call encoding and decoding methods statically.

use Tuupola\Base62Proxy as Base62;

$encoded = Base62::encode(random_bytes(128));
$decoded = Base62::decode($encoded);

$encodedInt = Base62::encodeInteger(987654321);
$decodedInt = Base62::decodeInteger($encodedInt);

You can pass an $options array to the Base62 constructor to configure the underlying encoder. This is useful if you need to specify specific character sets or other encoder-specific behaviors.

use Tuupola\Base62;

$base62 = new Base62([
    // Add configuration options here
]);

The library defines two standard character sets as constants:

• Base62::GMP: The standard alphanumeric sequence 0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz.
• Base62::INVERTED: An inverted alphanumeric sequence 0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ.

// Standard alphanumeric
const GMP = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";

// Inverted alphanumeric
const INVERTED = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";