UUID Generator
Generate cryptographically secure UUID v4 (random) identifiers. Perfect for database keys, request IDs, or any unique identifier.
Generated UUIDs
Why distributed systems rely on UUIDs
A UUID is a 128-bit identifier designed to be unique without a central coordinator. That property is what makes it indispensable in distributed systems: two services on different machines can each mint an ID with effectively zero risk of collision, so you never need a shared sequence generator. UUIDs show up as database primary keys, correlation IDs that stitch a request across microservices, idempotency keys and trace identifiers in observability pipelines.
Generate identifiers in your browser
This generator produces version 4 random UUIDs locally using your browsers cryptographic source, so each value is unpredictable and never transmitted. Random UUIDs are the safe default when you simply need uniqueness. If you need identifiers that sort by creation time, newer time-ordered schemes such as UUIDv7 improve database index locality, but v4 remains the right choice whenever ordering does not matter.
Common UUID mistakes and how to fix them
Using random UUIDs as clustered primary keys can fragment database indexes because inserts land in random positions; time-ordered UUIDs or a separate sequence solve that. Another mistake is assuming a UUID is secret, it is unique but not unguessable enough to act as an auth token. In tracing, reuse the same correlation ID across every hop of a request so the whole path is searchable. For wiring request IDs through your traces, see our OpenTelemetry tracing guide.
Frequently asked questions
Are UUIDs guaranteed unique?
Not absolutely, but a v4 UUID has 122 random bits, so a collision is astronomically unlikely in practice.
Should I use a UUID as a database key?
You can, but random UUIDs hurt index locality. Consider a time-ordered UUID scheme for high-insert tables.
Is a UUID secure enough to be a token?
No. It is unique but should not be treated as a secret. Use a dedicated token for authentication.
What is the difference between v4 and v7?
v4 is fully random; v7 embeds a timestamp so IDs sort by creation time, improving database performance.