How to generate UUIDs
- Enter how many UUIDs you need (1–1,000).
- Choose formatting: uppercase, with or without hyphens, and optionally wrapped in braces.
- Click Generate UUIDs. Each has its own Copy button.
- Use Copy all or Download .txt to export the list.
About version 4 UUIDs
A UUID (universally unique identifier), also called a GUID, is a 128-bit value written as 32 hexadecimal digits in five groups, like 3f2b8c1e-9d4a-4f7e-b2c1-8a6d5e4f3c21. Version 4 UUIDs are random: 122 of the bits come from a random source, and the rest mark the version (the “4”) and variant. The chance of two random v4 UUIDs ever colliding is so small that they are used as unique IDs across databases and distributed systems without coordination.
This UUID generator uses crypto.randomUUID() where available and falls back to crypto.getRandomValues() with the version and variant bits set as RFC 9562 specifies. Both are cryptographically secure sources. Formatting options change only how UUIDs are displayed, not their values.
Common uses
- Primary keys and record IDs in databases.
- Unique file names, upload keys and session identifiers.
- Test data and fixtures for software development.
- Correlation IDs for logs and API requests.
UUID generator FAQ
Are these UUIDs truly unique?
For practical purposes, yes. You would need to generate billions per second for many years before a collision becomes likely.
What’s the difference between a UUID and a GUID?
They are the same thing. GUID is the name Microsoft uses.
Should I use UUIDs for secrets?
Use the Password Generator for secrets and passwords. UUIDs are designed as identifiers, not passwords.