GUID Generator

Generate, format, validate and export GUIDs for Microsoft systems, databases, and general use.

All Tools
v4 is random (standard GUID). v7 is time-ordered. v1 is time+node. ULID is sortable and URL-friendly.
Up to 500 IDs at once.
GUID v5 (Name-based)
Same namespace + same name always produces the same GUID.
Validate / Normalize
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List

What is a GUID Generator?

A GUID (Globally Unique Identifier) Generator produces unique reference numbers used in Microsoft technologies, databases (SQL Server), and distributed systems (COM/DCOM). A GUID is essentially the Microsoft implementation of the UUID standard (RFC 4122).

Most modern systems use "Version 4" (random) GUIDs. This tool also supports the newer "Version 7" (time-ordered), which is excellent for database primary keys as it reduces index fragmentation.

Are GUIDs and UUIDs the same?

Effectively, yes. GUID is the term used in the Microsoft ecosystem, while UUID is the term used in Linux, Java, and open standards (RFC 4122).

  • They are both 128-bit integers.
  • They are both typically displayed as 32 hex digits with hyphens (8-4-4-4-12).
  • A standard "GUID" in C# Guid.NewGuid() is a UUID v4.

Best practices for GUIDs

  • Use v4 (Random): For general uniqueness where order doesn't matter.
  • Use v7 (Time-Ordered): For database Primary Keys (PK) to improve INSERT performance.
  • Format: SQL Server often uses uniqueidentifier. In text, hyphens are standard.
  • Security: GUIDs are unique but not "secret"—don't use them as passwords or API keys alone.

Frequently Asked Questions (FAQ)

1. How do I generate a GUID in C#?

Use Guid.NewGuid(). This creates a version 4 (random) GUID.

2. How do I generate a GUID in SQL Server?

Use NEWID() for a random GUID (v4-like). Use NEWSEQUENTIALID() for a sequential one (similar benefits to v7).

3. Is a GUID unique?

Yes. The probability of collision (two generated GUIDs being identical) is microscopically small, enough to be considered impossible for practical purposes.

4. What is a "nil" or "empty" GUID?

It is a GUID with all zeros: 00000000-0000-0000-0000-000000000000. In C#, this is Guid.Empty.

5. Is this tool secure?

Yes. All GUIDs are generated locally in your browser using the crypto API. We do not transmit or store them.

Quick guide
  • GUID v4: Random (standard).
  • GUID v7: Time-ordered (modern).
  • ULID: Sortable, compact (26 chars).
Common formats
550e8400-e29b-41d4-a716-446655440000
{550e8400-e29b-41d4-a716-446655440000}
urn:uuid:550e8400-e29b-41d4-a716-446655440000