UUID v7 generator

The Randogram UUID generator produces a universally unique identifier of version 7.
A version 7 UUID starts with Unix time in milliseconds — that is 48 bits — and fills the remaining bits at random. The identifiers sort by creation time yet disclose neither the node nor a counter. This is the recommended choice when you need both a unique key and insertion order: the database index grows from one end.
You can also use the public UUID generator API

Questions and answers

Can I read the creation time out of a version 7 UUID?
Yes, the first 48 bits are Unix time in milliseconds, and getting them out takes no keys at all. That is convenient for internal keys, but for public links it is worth remembering that the moment of creation is visible to anyone who sees the identifier.
Is version 7 a good primary key?
Yes, that is what it is for. The values grow along with time, so inserts go to one edge of the index instead of scattering across it the way version 4 does. Meanwhile 74 bits stay random, so a neighbouring key cannot be guessed from a known one.
What happens when several identifiers are created in the same millisecond?
Their top 48 bits match and they differ in the random bits, so they stay unique. The order within a single millisecond is not guaranteed, though: if it matters, keep a separate sequence field alongside.