UUID/GUID Generator
Generate UUID/GUID entirely in your browser — v1, v4, v7, Empty, and GUID formats.
A UUID (Universally Unique Identifier, also called a GUID) is a 128-bit value usually written as a 32-character hex string with hyphens, e.g. 550e8400-e29b-41d4-a716-446655440000. This tool supports five formats: v1 (timestamp + node — legacy, sortable), v4 (random — the most common), v7 (timestamp + random — RFC 9562 modern, sortable), Empty (all-zeros sentinel), and GUID (same generation as v4 — Windows/.NET compatibility name).
Fully random — the default choice.
1 - 1000
FAQ
Can UUIDs collide?
In theory there's a tiny chance, but v4/v7 UUIDs have 122 random bits (~2^122 possible values), so in practice collisions are not a real concern.
How do v1, v4, and v7 differ?
v1 is the legacy time-ordered scheme based on a timestamp and a node id; it can leak machine info and generation time, but is still common in older systems. v4 is fully random — the simplest and most common version. v7 is the RFC 9562 modern scheme: a Unix timestamp prefix with random bits after, sortable like v1 but without the node leak. v7 is the right pick for new database primary keys.
Is a UUID the same as a GUID?
Yes. GUID is Microsoft's term for the UUID standard. The 'GUID' option here uses the same generation as v4 — it's the same 128 bits, just exposed under the name Windows and .NET tooling searches for.
What's the Empty UUID used for?
The all-zeros UUID (00000000-0000-0000-0000-000000000000) is commonly used as a 'no value' placeholder — for example, writing into a NOT NULL column when the real value isn't known yet, marking 'unrelated' on a message queue, or stubbing out test fixtures. It's structurally valid but obviously not random.