What does it do?
It generates UUIDs (universally unique identifiers) in version 4 (random) or version 7 (time-ordered), one at a time or up to 1,000 at once, and inspects any UUID you paste: it validates it and tells you its version, its variant and, for time-based versions (1, 6 and 7), when it was created.
How to use it
- Choose v4 or v7 and how many you need. Toggle upper case, hyphens or braces to match your codebase.
- Copy the list, or press Regenerate for a new batch.
- Paste any UUID on the left to inspect it.
Anatomy of a UUID v7
0190a5b8-6e1f-7c3a-9b2d-4e5f6a7b8c9d
└──────┬─────┘ │ └┬┘ │
Unix ms (48 bits) │ │ └ variant (10xx)
version 7 random
Frequently asked questions
›Should I use UUID v4 or v7?
Use v7 for database primary keys: it starts with a timestamp, so new rows are inserted in order and indexes stay compact. Use v4 when you do not want the creation time to be visible.
›Can two UUIDs collide?
In theory yes, in practice no: a v4 has 122 random bits. You would need to generate about 2.7 quintillion of them to have a 50% chance of a single duplicate.
›Are the generated UUIDs secure?
They use crypto.getRandomValues, a cryptographically secure generator. Still, a UUID is an identifier, not a secret: do not use it as a password or an API key.