Generate unique UUID v4 identifiers. Fast, secure, and completely free. All processing happens in your browser — no data is sent to any server.
A UUID Generator produces universally unique identifiers — 128-bit values conventionally written as 32 hexadecimal digits grouped into five sections (like 550e8400-e29b-41d4-a716-446655440000) — that are, for all practical purposes, guaranteed unique across systems without needing a central coordinating authority. Different UUID versions generate that uniqueness differently: version 4 relies on randomness, while version 1 and version 7 incorporate a timestamp, which matters if you need IDs that also sort roughly in creation order.
Any system that needs to assign unique identifiers without a central database auto-increment sequence — a distributed system generating IDs on multiple nodes, a client-side app creating a record before it's ever synced to a server, a test suite that needs guaranteed-unique fixture IDs — relies on UUIDs specifically because two independently generated UUIDs will, in practice, never collide. Generating a quick batch here is faster than writing a one-line script every time you need a handful for a test or a manual database insert.
No — UUIDs are identifiers, not secrets. Even random v4 UUIDs aren't generated with the same security guarantees or entropy budget as a purpose-built secret token, and they're often exposed in URLs or logs, so never use a UUID as an authentication credential.
v1 incorporates a timestamp and the generating machine's MAC address (which can leak information); v4 is purely random with no embedded metadata; v7 is a newer variant that embeds a timestamp for natural sort order while still including substantial randomness, making it popular for database primary keys.
For version 4 UUIDs, the probability is astronomically small — with 122 random bits, you'd need to generate billions of UUIDs per second for millions of years before a collision became likely, which is why they're treated as effectively unique in practice.
The hyphenated format (8-4-4-4-12 hex digits) is the standard human-readable representation defined by the UUID specification, though many systems also accept the same value without hyphens as a compact 32-character string.
Yes, generation uses the browser's Web Crypto API where available, which provides cryptographically strong randomness rather than a weaker pseudo-random number generator.