Free tools
UUID generator & inspector
Generate random v4 or time-ordered v7 identifiers, one at a time or ten thousand at once, and decode any UUID you already have.
Processed by Ironfang in the UK. Nothing you submit is stored or logged.
Inspect a UUID
How these UUIDs are made
Values are generated by our Go API using the operating system's cryptographic random source - never a seeded pseudo-random generator. v7 identifiers follow RFC 9562: the first 48 bits are the Unix timestamp in milliseconds, so values created in sequence sort in creation order, which is why we use v7 for database keys in our own products. Generated values are returned to you and forgotten; they are not logged, stored or added to analytics.
v4 or v7?
v4 is 122 bits of pure randomness and reveals nothing about when it was made. v7 trades 48 of those bits for a timestamp, which makes B-tree indexes append-friendly and lets you recover creation time from the identifier itself - the inspector above does exactly that. If identifiers must not leak timing, use v4; if they are database keys, v7 is usually the better default. See RFC 9562 for the full definitions.
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