Free UUID generator — v4, v7, v1, NIL
Cryptographically secure v4 (random), time-sortable v7 for databases, v1 legacy, NIL. Bulk up to 10,000. Decode v1/v7 to extract timestamps.
Uses crypto.getRandomValues — same primitive as Node.js crypto. Nothing sent, nothing stored.
Frequently asked
v4 vs v7 — which should I use?
v7 if you're using it as a database key — the timestamp prefix means indexes stay clustered (huge insert perf win vs v4). v4 if you just need pure random with no correlation.
Is v1 safe?
v1 leaks the timestamp + MAC address of the generating machine. Only use for legacy compatibility. Prefer v7 for time-sortable.
What's NIL UUID?
All zeros: 00000000-0000-0000-0000-000000000000. Used as a placeholder / null value.
How random is v4?
122 bits of randomness from crypto.getRandomValues. Collision probability negligible even at billions of UUIDs.
Any dependencies?
Zero. Native browser APIs only.
Free?
Yes.