Is UUID v4 truly unique?

UUID v4 is randomly generated, so there's no guarantee of uniqueness, but the probability of a collision is astronomically low (1 in 5.3 × 10^36 for any two UUIDs). For practical purposes, treat them as unique.

What's the difference between UUID and GUID?

They're the same thing. GUID (Globally Unique Identifier) is Microsoft's term for UUID. Both follow the same RFC 4122 standard and are interchangeable.

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Generators

UUID Generator

Generate cryptographically random UUID v4 identifiers in bulk — perfect for database primary keys.

Last updated July 1, 2026

How to use UUID Generator

1Choose how many UUIDs to generate (1 to 1,000).
2Select your preferred format: standard, uppercase, or without dashes.
3Click 'Generate' and copy individual UUIDs or the entire list.

Why use this tool

Uses the browser's crypto.randomUUID() API — cryptographically secure, not Math.random().
Bulk generation up to 1,000 UUIDs in one click.
Three format options: standard, uppercase, and no-dashes.
Copy all at once or copy individual entries.

Use cases

Pre-generating database IDs

Generate a batch of UUID primary keys offline for seeding a database migration or populating a fixture file.

Creating test data

Quickly generate unique identifiers for test payloads in unit or integration tests without running a server.