GUID Generator
Generate cryptographically secure, random version-4 GUIDs directly on your device — singly or in bulk.
What is a GUID?
A GUID (Globally Unique Identifier) is a 128-bit value used to identify objects with practical uniqueness — no central registry required. It is Microsoft's name for a UUID (Universally Unique Identifier, RFC 4122), and the two terms describe the same thing. This free GUID generator creates cryptographically secure version-4 GUIDs directly on your device using crypto.getRandomValues() — nothing is sent to any server.
Where GUIDs are used
- .NET / C#:
Guid.NewGuid()for entity keys, correlation IDs and message deduplication - SQL Server: the
uniqueidentifiercolumn type andNEWID() - COM & Windows: interface IDs (IIDs), class IDs (CLSIDs) and registry keys
- Distributed systems: database keys that can be generated on any node without coordination
.NET GUID format specifiers
- N — 32 digits:
00000000000000000000000000000000(use the "Include Hyphens" toggle off) - D — hyphenated (default):
00000000-0000-0000-0000-000000000000 - B — braces:
{00000000-0000-0000-0000-000000000000} - P — parentheses:
(00000000-0000-0000-0000-000000000000)
Generate with hyphens here and wrap in braces or parentheses as needed; use the Uppercase toggle for registry-style GUIDs.
How unique is "globally unique"?
A version-4 GUID contains 122 bits of randomness — about 5.3 undecillion (5.3×1036) possible values. Generating one billion GUIDs per second, you would statistically need over 85 years to reach a 50% chance of one collision. That is why GUIDs are safely generated independently on any machine.
Frequently Asked Questions
Is a GUID the same as a UUID?
Functionally yes — UUID is the standard term (RFC 4122); GUID is Microsoft's name for the same 128-bit identifier used in .NET, COM, SQL Server and Windows.
Are these GUIDs cryptographically secure?
Yes. They are produced with your browser's crypto.getRandomValues(), a cryptographically secure random source, entirely on your device.
Can two GUIDs collide?
With 122 random bits, you would need about 2.7×1018 GUIDs for a 50% collision chance — for practical purposes GUIDs are unique.