GUID Generator
Generate Globally Unique Identifiers for Microsoft ecosystems
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Click "Generate" to create UUIDs
UUID v4
Random UUIDs. Most commonly used for general purposes.
UUID v7
Time-ordered and random. Best for databases and sorting.
ULID
Sortable 26-char IDs. Perfect for distributed systems.
NanoID
Compact 21-char URL-safe IDs. Great for frontend use.
{550E8400-E29B-41D4-A716-446655440000}What is GUID?
GUID (Globally Unique Identifier) is Microsoft's implementation of the UUID standard. While technically identical to UUID, GUID is the preferred terminology in Windows, .NET, and Microsoft SQL Server environments. The format and generation algorithms are the same.
Microsoft introduced GUIDs in the early 1990s for COM (Component Object Model) to uniquely identify interfaces, classes, and type libraries. Today, they're ubiquitous in Windows development, from registry keys to database primary keys.
Why Use GUID?
Use the term "GUID" when working in Microsoft ecosystems for consistency with documentation, APIs, and team conventions. .NET's System.Guid class, SQL Server's uniqueidentifier type, and Windows APIs all use GUID terminology.
For database-generated GUIDs in SQL Server, consider NEWSEQUENTIALID() instead of NEWID() for better index performance—it generates time-ordered GUIDs similar to UUID v7.
How GUID Works
GUID generation in .NET:
// Generate random GUID (equivalent to UUID v4) Guid.NewGuid()
// Parse from string Guid.Parse("550e8400-e29b-41d4-a716-446655440000")
// Format options guid.ToString("N") // No hyphens: 550e8400e29b41d4a716446655440000 guid.ToString("B") // Braces: {550e8400-e29b-41d4-a716-446655440000}
Common Use Cases
- .NET application identifiers
- SQL Server primary keys
- Windows registry entries
- COM/ActiveX component registration
Pro Tip
In SQL Server, use NEWSEQUENTIALID() for clustered index keys to avoid page fragmentation.
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