Universally Unique Identifiers are 128-bit IDs that can be generated anywhere without coordination. Generate one, or a thousand, using your browser's secure random generator.
How to use the UUID Generator
- 1 A fresh UUID appears at the top — click New for another.
- 2 Set a quantity and format options for bulk generation.
- 3 Copy or download the list, or paste a UUID to validate it.
Formula
xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx
4 = version, y ∈ {8, 9, a, b} = RFC 9562 variant
122 random bits
Worked examples
Input: Generate
Result: e.g. 3b241101-e2bb-4255-8caf-4136c566a962
Random every time
How unique is a UUID v4?
A version 4 UUID has 122 random bits. You would need to generate about 2.7 × 10¹⁸ UUIDs to have a 50% chance of a single collision — for practical purposes they are unique.
UUID vs. GUID
GUID is Microsoft's name for the same 128-bit identifier format. They are interchangeable; GUIDs are often written in uppercase with braces.
Runs locally
Everything happens in your browser — nothing you paste is uploaded or logged, so it is safe to use with API responses, tokens and internal data.
Frequently asked questions
Are these UUIDs secure?
They are generated with the Web Crypto CSPRNG, so they are unpredictable. Still, do not use UUIDs as secret tokens on their own.
Can I use UUIDs as database primary keys?
Yes, though random v4 keys can fragment B-tree indexes; time-ordered UUID v7 is often preferred for that.
What is the nil UUID?
00000000-0000-0000-0000-000000000000, a special value meaning "no UUID".
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