UUID v4 — random
A standard UUID built from 122 random bits. The most widely used version, with a collision probability that is virtually zero.
UUID v7 — time-sorted
Stores Unix milliseconds in the first 48 bits so IDs sort by creation order. Great for database primary keys and indexes.
ULID
26-character Crockford Base32. Sorts lexicographically = chronologically, and is a compact identifier that fits URLs and file names.
Secure randomness
Based on crypto.randomUUID() / getRandomValues. Generated only in your browser, with nothing sent to a server.