A GUID (Globally Unique Identifier) is Microsoft’s name for a UUID. A randomly generated GUID is functionally identical to a UUID version 4 — a 128-bit value with 122 bits of randomness — and is widely used across Windows, .NET, SQL Server, and COM.
This generator creates GUIDs in your browser in the standard 8-4-4-4-12 hexadecimal format. They are ready to paste into C#, T-SQL, the registry, or configuration files.
GUID vs UUID
There is no technical difference between a GUID and a UUID; the two terms describe the same 128-bit identifier. "UUID" is the term used in IETF standards, while "GUID" is the term Microsoft adopted across its platforms.
In .NET you create one with Guid.NewGuid(); in SQL Server with NEWID(). Both return the same kind of value this tool generates.
GUID formatting
GUIDs are usually displayed as 32 hexadecimal digits in five groups, sometimes wrapped in braces, e.g. {3F2504E0-4F89-41D3-9A0C-0305E82C3301}. Microsoft tooling accepts several formats but the hyphenated form shown here is the most common.
Because a GUID is just a UUID, you can store it in any UUID-capable column and interoperate with non-Microsoft systems without conversion.
Frequently asked questions
- Is a GUID the same as a UUID?
- Yes. GUID and UUID refer to the same 128-bit identifier. GUID is simply Microsoft’s terminology.
- What UUID version is a GUID?
- A randomly generated GUID corresponds to UUID version 4. Some Microsoft tools historically produced other variants, but v4 is standard today.
- Are GUIDs case-sensitive?
- No. The hexadecimal digits in a GUID can be uppercase or lowercase and still refer to the same value.