UUID generator
Create random, practically unique version 4 UUID identifiers, one or many at a time, with format options.
100% in your browser — nothing is sent to any serverGenerate UUID
From 1 to 1000 UUIDs per generation.
What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit identifier shown as 32 hexadecimal digits grouped in 5 blocks, for example 550e8400-e29b-41d4-a716-446655440000. It identifies resources uniquely without needing a central server to hand out IDs.
Version 4 is generated with random bits (cryptographically, when the browser allows), so the chance of two v4 UUIDs colliding is virtually zero: on the order of 1 in 2.7 × 10³⁶².
Where they are used
- Database primary keys when you don't want a sequential counter.
- Session IDs, tokens and distributed traces.
- Anywhere you need a unique ID without coordination between systems.
Frequently asked questions
What is a UUID v4?
It is a 128-bit identifier generated with random bits (cryptographically, when the browser allows it), defined by RFC 4122. It is shown as 32 hexadecimal digits grouped in 5 blocks.
Can UUIDs come out repeated?
The probability is practically zero: on the order of 1 in 2.7 × 10³⁶². For any practical use they are considered unique without needing to check.
How many can I generate at once?
From 1 to 1000 per generation, in any format: with hyphens, in uppercase, or in braces.
Are the UUIDs sent to any server?
No. They are generated in your browser with crypto.getRandomValues and never leave your device.