Generate UUIDs (v1, v4, v5, v7)

UUIDs (Universally Unique Identifiers) are unique identifiers used to guarantee uniqueness across different systems and databases without requiring central coordination. They are commonly used in distributed systems and web applications to generate unique identifiers for resources.

This tool supports the following UUID versions:

• Version 1: based on timestamp and MAC address.
• Version 4: generated randomly (the most used).
• Version 5: based on a SHA-1 fingerprint of a namespace and a name (deterministic: the same namespace + name pair will always produce the same UUID).
• Version 7: time-ordered, recommended for modern database primary keys (lexicographic sort = chronological sort).

To generate a UUID v5, you must pick a standard namespace and provide a name:

• DNS: to use when the name is a domain name (for example cdrn.fr).
• URL: to use when the name is a URL (for example https://cdrn.fr/).
• OID: to use when the name is an ISO object identifier.
• X500: to use when the name is an X.500 distinguished name.

Since generation is deterministic, UUID v5 is particularly suited to producing reproducible identifiers from stable data.

On the home page, you can generate UUIDs by selecting the desired version from a dropdown and clicking the generate button. For version 5, also provide the namespace and the name.

As soon as a UUID is generated, it will appear in a green result line indicating that it was generated successfully. If an error occurs, a red line will display the matching error message.

You can use the generated UUIDs in your applications by integrating them directly in your code. Here is a PHP example:

<?php
use Ramsey\Uuid\Uuid;

// Generate a UUID v4 (random)
$uuidV4 = Uuid::uuid4();

// Generate a UUID v5 (deterministic from a namespace and a name)
$uuidV5 = Uuid::uuid5(Uuid::NAMESPACE_DNS, 'cdrn.fr');

// Generate a UUID v7 (time-ordered)
$uuidV7 = Uuid::uuid7();

echo "UUID v4: " . $uuidV4->toString() . PHP_EOL;
echo "UUID v5: " . $uuidV5->toString() . PHP_EOL;
echo "UUID v7: " . $uuidV7->toString() . PHP_EOL;
?>

    

You can also validate and analyse existing UUIDs to determine their version and validity. Here is a PHP code example:

<?php
use Ramsey\Uuid\Uuid;

// Validate a UUID
$uuidString = '123e4567-e89b-12d3-a456-426614174000';
if (Uuid::isValid($uuidString)) {
    $uuid = Uuid::fromString($uuidString);
    echo "Valid UUID of version: " . $uuid->getFields()->getVersion();
} else {
    echo "Invalid UUID";
}
?>