online GUID generator

What is a GUID?

GUID stands for Globally Unique Identifier.

A GUID is a 16-byte (128-bit) number. A GUID is represented by 32 hexadecimal digits, displayed in five groups separated by hyphens, in the form 8-4-4-4-12 for a total of 36 characters (32 digits and four hyphens). [ Wikipedia ]

Example: 956ea8a9-5eb5-4012-be9e-727aaf4d9121

How Unique is a GUID?

GUIDs are VERY unique!

There are 340,282,366,920,938,463,463,374,607,431,768,211,456 possible GUIDs (16 to the 32nd power), or about 3 × 1038.

"...after generating 1 billion GUIDs every second for the next 100 years, the probability of creating just one duplicate would be about 50%. The probability of one duplicate would be about 50% if every person on earth owns 600 million GUIDs."
"The total number of unique keys is 2128 or 3.4×1038. This number is so large that the probability of the same number being generated randomly twice is negligible; however, GUID numbers are not always generated randomly."

What are GUIDs used for?

If you're at this page, you probably already know, but - in case you were searching for GUID (Grandmas Under the Influence of Dolphins), and found this instead, this is for you.

GUIDs are idenfication numbers used in the computer / programming industry often as the primiary key of a database table. Confused? How about in simpler terms: It's a VERY unique number that computer geeks (and proud of it!) use to make sure their geeky data doesn't get mixed up with other geeky data.

What's the difference between a GUID and a UUID?

A UUID (Universally unique identifier) is usually synonymous with GUID, but GUID can also refer to Microsoft's version of a UUID.