A UUID (Universally Unique Identifier) is a 128-bit identifier formatted as 32 hex digits in groups: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx. Version 4 UUIDs are randomly generated.

How unique is a UUID v4?

The probability of generating two identical UUIDs is astronomically small — roughly 1 in 5.3 × 10³⁶. You can safely treat them as unique.

What is the difference between UUID and GUID?

GUID (Globally Unique Identifier) is Microsoft's term for UUID. They are effectively the same thing.

UUID Generator

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Free online UUID v4 generator. Generate one or multiple random UUIDs (Universally Unique Identifiers) with a single click. Choose uppercase or lowercase, with or without hyphens. Uses the browser's secure random number generator.

Count (max 20)

Hyphens

Uppercase

9b5e0377-8ae4-4148-a9d3-35b8037a59bc

5ce18e7e-3ad7-4f2b-8a0c-ece128972019

89823a5e-da32-4b14-9878-7ee94adbb6a8

ab83e479-affc-4959-b3d6-c63c46747112

f813ae2f-e303-4ddc-86db-4df5808d0159

Frequently Asked Questions

References

RFC 9562 — Universally Unique IDentifiers (UUIDs) — IETF
crypto.randomUUID() — MDN Web Docs

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Frequently Asked Questions

References and sources

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