What this tool does
A UUID (Universally Unique Identifier), also called a GUID, is a 128-bit identifier rendered as 36 characters in the form xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx. This generator produces RFC 4122 version 4 UUIDs, where the random bits are filled by your browser’s CSPRNG. UUIDs are designed to be unique across space and time without a central coordinator, which makes them handy whenever you need a fresh identifier and cannot easily ask a server for one.
How to use it
- Open the page — a UUID is generated automatically on load.
- Click Generate New to draw another, as many times as you need.
- Click Copy to Clipboard to grab the current value, then paste it into your database row, document ID, or config file.
Example
A typical version 4 UUID looks like f47ac10b-58cc-4372-a567-0e02b2c3d479. The “4” in the third group marks it as version 4, and the leading digit of the fourth group is always 8, 9, a, or b, which fixes the variant. With 122 random bits, the chance of two independently generated UUIDs colliding is vanishingly small for any realistic workload.
Limitations
- UUIDs are identifiers, not secrets. They are unique, not unguessable in the way a password must be — do not use a UUID as an API key or password.
- Uniqueness is probabilistic, not absolute. For extremely high-volume generation, pair the UUID with a uniqueness check in your data store.
- Version 4 UUIDs reveal nothing about where or when they were made, which is good for privacy but means they cannot be sorted by creation time.
Frequently Asked Questions
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