How to Generate GUIDs in PHP

Quick guide on generating GUIDs in PHP using the ramsey/uuid package.

Prerequisites

PHP 7.2 or later
Composer

Installation

Install the ramsey/uuid package

composer require ramsey/uuid

Generating GUIDs

PHP doesn’t have built-in support for generating all versions of UUIDs. The ramsey/uuid library provides an easy and performant way to generate UUIDs of different versions.

UUID v1 (Time-based)

require 'vendor/autoload.php';

use Ramsey\Uuid\Uuid;

$uuid1 = Uuid::uuid1();

echo "UUID v1: " . $uuid1->toString() . PHP_EOL;

UUID v3 (Name-based, MD5)

require 'vendor/autoload.php';

use Ramsey\Uuid\Uuid;

$namespace = Uuid::NAMESPACE_DNS;
$name = "example.com";
$uuid3 = Uuid::uuid3($namespace, $name);

echo "UUID v3: " . $uuid3->toString() . PHP_EOL;

UUID v4 (Random)

require 'vendor/autoload.php';

use Ramsey\Uuid\Uuid;

$uuid4 = Uuid::uuid4();

echo "UUID v4: " . $uuid4->toString() . PHP_EOL;

UUID v5 (Name-based, SHA1)

require 'vendor/autoload.php';

use Ramsey\Uuid\Uuid;

$namespace = Uuid::NAMESPACE_DNS;
$name = "example.com";
$uuid5 = Uuid::uuid5($namespace, $name);

echo "UUID v5: " . $uuid5->toString() . PHP_EOL;

Formatting GUIDs

The ramsey/uuid library outputs UUIDs in the standard 8-4-4-12 format by default. For other formats, you can modify the string representation.

Formatting UUID with braces

$uuid4 = Uuid::uuid4();
$uuidWithBraces = sprintf('{%s}', $uuid4->toString());

echo "UUID with braces: " . $uuidWithBraces . PHP_EOL;

Tips for working with GUIDs in PHP

Use ramsey/uuid over custom implementations: The ramsey/uuid library is a well-tested and widely used solution for generating UUIDs in PHP, making it more reliable and performant than custom implementations.
Prefer UUID v4 (random-based) for most use cases: UUID v4 provides a good balance of uniqueness and randomness without relying on a specific system’s clock or hardware.
Be aware of the string representation: When storing or transmitting UUIDs as strings, be mindful of the format being used to avoid potential compatibility issues.
Use a namespace and a name that are unique and consistent to generate UUID version 5.
Use the same UUID generation method consistently throughout your application.
Store GUIDs as strings, not binary data.