UUID / GUID Generator
Generate standards-compliant version 4 UUIDs (also called GUIDs) instantly, using your browser's cryptographically secure random source.
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How the UUID / GUID Generator works
This generates RFC 4122 version 4 UUIDs: 122 random bits plus 6 fixed version/variant bits, arranged in the standard 8-4-4-4-12 hyphenated hex format. The random bits come from the Web Crypto API, giving a genuinely negligible chance of collision — the odds of two version-4 UUIDs ever matching are effectively zero even across trillions of generated values.
UUIDs generated this way are suitable for database primary keys, distributed system identifiers, session tokens, and any situation calling for a unique identifier that multiple independent systems can generate without coordinating with each other.
How to use it
Frequently asked questions
What's the difference between a UUID and a GUID?
They're effectively the same concept — GUID is Microsoft's historical name for what the rest of the industry calls a UUID, following the same RFC 4122 structure.
Could two generated UUIDs collide?
The probability is astronomically small — version 4 UUIDs have 122 random bits, so collisions are not a practical concern even at massive scale.
Are these safe to use as database primary keys?
Yes, version 4 UUIDs are commonly used as primary keys, particularly in distributed systems where coordinating sequential IDs across servers is impractical.