String Generator

Fast, cryptographically-secure random string generator for PHP 8.2+.

Zero external dependencies. Uses random_bytes() with bit-packing and rejection sampling for efficient, unbiased output.

Installation

composer require taranovegor/string-generator

Quick start

use TaranovEgor\StringGenerator\Alphabet;
use TaranovEgor\StringGenerator\StringGenerator;

$generator = new StringGenerator();

// Default — alphanumeric (a-zA-Z0-9)
$token = $generator->generate(32);

// Digits only
$pin = $generator->generate(6, Alphabet::Digits);

// Letters only
$code = $generator->generate(16, Alphabet::Alpha);

// All printable ASCII
$password = $generator->generate(20, Alphabet::Printable);

All predefined alphabets

Case	Characters	Size
Digits	0-9	10
AlphaLower	a-z	26
AlphaUpper	A-Z	26
Alpha	a-z A-Z	52
Alphanumeric	a-z A-Z 0-9	62
Punctuation	32 punctuation characters (`!"#$%&'()*+,-./:;<=>?@[]^_{	}~`)
Printable	All printable ASCII (33–126)	94

Custom alphabet

Pass a string as the second argument — every byte in it becomes a valid character:

$generator = new StringGenerator();

// Hex string
echo $generator->generate(32, '0123456789abcdef');

// Base58
echo $generator->generate(22, '123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz');

// Binary-safe — works with any byte values, including null bytes
echo $generator->generate(64, "\x00\x01\x02\x03");

Note: the alphabet must contain at least 2 distinct bytes.

Development

composer install

# Run tests
composer test

# Static analysis (PHPStan level 9)
composer analyse

License

The scripts and documentation in this project are released under the MIT License