UUID generator
Generate UUIDs — v1 through v8 — and export in bulk.
Click Generate to create a UUID. Set Quantity up to 10,000 for bulk.
Validator & format converter
- Valid
- Version
- Variant
- Canonical
- No dashes
- Braces
- URN
About this tool
A UUID is a 128-bit identifier designed to be unique without coordination — useful for database primary keys, log correlation IDs, and file names that won't collide. The most common version is v4 (random), but v7 (timestamp-based and sortable) has become the modern pick for database IDs. This tool generates every RFC 4122 and RFC 9562 version — v1 through v8 — singly or in bulk up to 10,000 at a time. The v7 implementation is strictly monotonic, so even IDs generated in the same millisecond sort correctly — a detail most other generators get wrong.
Frequently asked questions
Should I use v4 or v7?
For new database primary keys, prefer v7 — it's sortable by creation time, which keeps indexes efficient and makes logs easier to scan. Use v4 when you explicitly want random IDs with no time leakage (e.g. share tokens, session IDs).
What is a namespace UUID for (v3 and v5)?
v3 and v5 are deterministic: given the same namespace and name, they always produce the same UUID. Useful when you need a stable identifier for an external name (a URL, a DNS entry, a file path) without keeping a mapping table.
Are these UUIDs really unique?
For v4, the odds of a collision between two random UUIDs are vanishingly small — you'd need to generate billions before the probability becomes non-trivial. v1/v6/v7 embed timestamps so same-moment generation on the same machine is handled by the clock sequence and counter fields.