UUID / GUID Generator
Generate v1, v4, v5 and v7 UUIDs instantly. All generated locally using the Web Crypto API - nothing is sent anywhere.
Version
Cryptographically random. No time info. Best for most uses.
Count
5Format
UUID Version Reference
v4 - Random
128 bits of cryptographic randomness. No timestamp, no location. Best general-purpose choice. Collision probability: astronomically low.
v7 - Time-ordered
First 48 bits are Unix timestamp (ms). Lexicographically sortable by creation time. Ideal for database PKs - avoids index fragmentation.
v1 - Time-based
Encodes a 60-bit timestamp at 100ns resolution plus a simulated MAC address. Monotonically increasing per node.
v5 - Name-based
SHA-1 hash of namespace + name. Deterministic and reproducible. Same inputs always give the same UUID. Use for content-addressed IDs.