Skip to content

Maintenance Ruby 3.4 gets fixes, but no new features. Switch to Ruby 4.0 →

instance method

Random::Formatter#uuid_v4

uuid_v4

Alias of #uuid

Generate a random v4 UUID (Universally Unique IDentifier).

Example
require 'random/formatter'

Random.uuid #=> "2d931510-d99f-494a-8c67-87feb05e1594"
Random.uuid #=> "bad85eb9-0713-4da7-8d36-07a8e4b00eab"
# or
prng = Random.new
prng.uuid #=> "62936e70-1815-439b-bf89-8492855a7e6b"

The version 4 UUID is purely random (except the version). It doesn’t contain meaningful information such as MAC addresses, timestamps, etc.

The result contains 122 random bits (15.25 random bytes).

See RFC9562 for details of UUIDv4.

See also #uuid #uuid_v7 #urlsafe_base64 also in 4.1 · 4.0 · 3.3