Base Class and Interfaces

Base class

Arokettu\Uuid\AbstractUuid class and Arokettu\Uuid\Uuid interface.

Direct creation

The base constructor is inherited by most of the descendants. It accepts a string of lowercase hexadecimal digits (0-9, a-f):


use Arokettu\Uuid\GenericUuid;

// {12345678-9abc-def0-1234-56789abcdef0}
$uuid = new GenericUuid('123456789abcdef0123456789abcdef0');


UuidParser::fromRfcFormat() and UuidParser::fromRfcFormat() can parse UUIDs/ULIDs in hex in case-insensitive manner.

Subclasses may also check the string for additional validity.

Conversion to Bytes

Added in version 1.2: toGuidBytes()

Methods to convert UUID object to a byte sequence:

  • toBytes() to the raw big-endian byte sequence

  • toGuidBytes() to the Microsoft GUID mixed-endian byte sequence

Conversion to String

Added in version 2.1: toDecimal()

Methods to convert UUID object to string:

  • toString(). Converts UUIDs to the RFC Format and ULIDs to Base32.

  • toRfcFormat() to RFC 9562 form. Aliases: toRfc4122(), toRfc9562(). Example: "6ba7b811-9dad-11d1-80b4-00c04fd430c8"

  • toBase32() to Base32. Example: "3BMYW137DD278R1D00R17X8C68"

  • toDecimal() to decimal. Example: "143098242483405524118141958906375844040"


toDecimal() can be used to create OID representation of the UUID:


// add OID UUID prefix: 2.25
$oid = '2.25.' . $uuid->toDecimal(); // 2.25.143098242483405524118141958906375844040


Methods to compare two UUID objects.

  • compare(): int. Returns same thing as strcmp.

  • equalTo(): bool. In strict mode (by default) returns true if bytes and types of the two objects are equal. In non-strict mode compares only byte values.


use Arokettu\Uuid\UlidParser;
use Arokettu\Uuid\UuidParser;

$uuid = UuidParser::fromString('6ba7b811-9dad-11d1-80b4-00c04fd430c8');
$ulid = UlidParser::fromString('3BMYW137DD278R1D00R17X8C68');

var_dump($uuid->compare($ulid)); // 0
var_dump($uuid->equalTo($ulid)); // false
var_dump($uuid->equalTo($ulid, strict: false)); // true


Added in version 1.1.

Changed in version 1.2: renamed from Rfc4122Variant1Uuid to Rfc4122Variant10xxUuid

Changed in version 3.0: renamed from Rfc4122Variant10xxUuid to Variant10xxUuid

RFC 9562 Variant 10xx UUID versions (all except for Nil and Max) extend this interface. This interface is most useful to check that it is a standard based UUID as opposed to Nil, Max, ULID or unrecognized generic.


use Arokettu\Uuid\Rfc4122Variant10xxUuid;
use Arokettu\Uuid\UlidFactory;
use Arokettu\Uuid\UuidFactory;

$uuid = UuidFactory::v4();
var_dump($uuid instanceof Variant10xxUuid); // true
var_dump($uuid->getVersion()); // 4

$ulid = UlidFactory::ulid();
var_dump($ulid instanceof Variant10xxUuid); // false


Changed in version 1.1: Now includes Nil and Max

Changed in version 3.0: No longer contains Max, UUIDv2, UUIDv6, UUIDv7, UUIDv8

All UUIDs mentioned in RFC 4122, i.e. Nil, and Variant10xxUuid versions 1-5 excluding 2.


Added in version 3.0.

All UUIDs mentioned in RFC 9562, i.e. Nil, Max, Rfc4122Variant10xxUuid versions 1-8 excluding 2. This excludes only Generic UUIDs and ULIDs.


UUIDv1, UUIDv2, UUIDv6, UUIDv7, and ULID extend this interface because they encode timestamp with various precisions:


use Arokettu\Uuid\UuidFactory;

$uuid = UuidFactory::v7();
var_dump($uuid->getDateTime()->format('c')); // current time