Frequently Asked Questions
What is a UUID?
UUID (Universally Unique Identifier) is a 128-bit identifier represented as 32 hex digits in 5 groups.
What are UUID versions?
v1 is time-based, v4 is random, and v5 is name-based (SHA-1). v4 is most common.
Is UUID v4 truly unique?
The collision probability is extremely low (about 1 in 2.71 quintillion).
What is UUID v5 used for?
v5 generates deterministic UUIDs from a namespace and name, always producing the same UUID.
Can I generate UUIDs without hyphens?
Yes. Use the format option to choose standard, no hyphens, uppercase, or braces.
How many UUIDs can I generate at once?
You can generate up to 100 UUIDs in a single batch.
What is a UUID namespace?
For v5, namespaces provide context: DNS, URL, OID, and X500.
Where are UUIDs used?
Databases, distributed systems, API identifiers, session tokens, and more.