GUID (UUID) Generator

GUID (or UUID) is an acronym for "Globally Unique Identifier" (or "Universally Unique Identifier"). It is a 128-bit integer number used to identify resources. The term GUID is generally used by developers working with Microsoft technologies, while UUID is used everywhere else.

128-bits is big enough, and the generation algorithm is unique enough that if 1,000,000,000 GUIDs per second were generated for 1 year the probability of a duplicate would be only 50%. Or if every human on Earth generated 600,000,000 GUIDs there would only be a 50% probability of a duplicate. (1)

Format

In its canonical textual representation, the 16 octets of a UUID are represented as 32 hexadecimal (base-16) digits, displayed in five groups separated by hyphens, in the form 8-4-4-4-12 for a total of 36 characters (32 hexadecimal characters and 4 hyphens). For example: (2)

123e4567-e89b-12d3-a456-426614174000
xxxxxxxx-xxxx-Mxxx-Nxxx-xxxxxxxxxxxx

Usage

require('GuidGenerator.php');

echo GuidGenerator::create();

Special Thanks

Based on the code by Alex Axil as commented on at PHP.net (3)

Bibliography

1. https://www.guidgenerator.com/
2. https://en.wikipedia.org/wiki/Universally_unique_identifier
3. https://www.php.net/manual/en/function.com-create-guid.php#99425