122 random bits from the browser's cryptographic generator. The usual choice when the ID does not need to sort.
Unix milliseconds + random (RFC 9562). Monotonic: UUIDs from the same millisecond still sort in creation order — good primary keys for databases.
Gregorian timestamp (100 ns), clock sequence and a random node (multicast bit set — no MAC address). v6 sorts by time; v1 only for systems that require it.
Version
Same namespace + name → always the same UUID. v5 hashes with SHA-1, v3 with MD5 (only for compatibility). The name is used exactly as entered, spaces included.
Version
Paste UUIDs (one per line, any spelling: braces, URN, without hyphens, Base64) to see version, variant, time and node.