UUID Generator
Generate one or many random version-4 UUIDs — the standard random unique identifier format used in databases, APIs, and software.
What a version-4 UUID is
A UUID (Universally Unique Identifier) is a 128-bit identifier formatted as 32 hexadecimal characters split into five groups. Version 4 means it's generated from random bits rather than derived from a timestamp or hardware address — with 122 random bits, the chance of two version-4 UUIDs ever colliding is astronomically small, which is why they're used as unique identifiers across distributed systems without needing central coordination.
Common uses
- Primary keys for database records
- Unique identifiers for API requests, sessions, or tracking IDs
- Generating unique filenames or temporary tokens
Frequently asked questions
How random is a UUID generated here?
It uses your browser's crypto.randomUUID() function, built on a cryptographically secure random number generator — the same quality of randomness used for security-sensitive purposes, not a weaker pseudo-random function.
Can two UUIDs generated by this tool ever be the same?
In theory yes, but in practice the odds are so small (roughly 1 in 2.7 undecillion for any two specific UUIDs to collide) that it's treated as effectively impossible for real-world purposes.
What's the difference between UUID versions?
Version 4 (generated here) is purely random. Other versions incorporate a timestamp, a namespace hash, or a MAC address instead — version 4 is the most commonly used when you just need a unique random identifier with no additional meaning encoded in it.
Can I generate UUIDs without the dashes?
Yes — tick "Remove dashes" to get a plain 32-character hexadecimal string instead of the standard dashed format, useful for systems that expect UUIDs without separators.