About this tool
Generates UUID version 4 identifiers, 36-character unique random strings used to unambiguously identify any entity in a system. Useful for database primary keys, anonymous user identifiers, temporary file names, session tokens, or any case where you need to guarantee two identifiers never clash.
How to use
- Click the button to generate a new UUID.
- Copy the result with one click.
- Generate as many as you need, each is independent of the previous one.
Frequently asked questions
- What format is generated?
- UUID version 4, in canonical format: 8 characters, hyphen, 4 characters, hyphen, 4 characters, hyphen, 4 characters, hyphen, 12 characters. 36 characters total including the 4 hyphens. Characters are hexadecimal (0-9, a-f).
- Can I get two identical UUIDs?
- In theory yes, in practice no. The UUID v4 space is large enough (around 5 × 10^36 possible values) that two random generations colliding is astronomically unlikely. For all practical purposes, you can assume every generated UUID is unique.
- What's the difference between UUID v4 and other versions?
- Several versions exist: v1 is based on timestamp and network address, v3 and v5 are based on hashing a name, v4 is purely random, v7 is a recent version that includes a timestamp for ordering. V4 is the standard choice when you don't need ordering or derivation from other values.